Sweet potato cake with brown butter frosting

On the lookout for the best fall cake recipe? Look no further. This sweet potato cake with brown butter frosting has everything you need for a cozy sweet pause with a cup of tea on an autumn afternoon. Roasted sweet potato mash is one of the key ingredients of the cake, together with coarsely ground cardamom. The frosting has the unexpected flavour of browned butter, and if you ask me, there is nothing that could pair better with the sweet potato cardamom cake base. Your family and friends will love it at Thanksgiving!

Sweet potato cake with brown butter frosting.

Brown butter frosting on brown butter cake

If you haven’t yet jumped on the brown butter bandwagon, you should. I have been a huge fan of this delicious twist to regular butter I almost can’t live without it. Especially since I moved to Sweden, where butter is generally salted. Salted brown butter is everything, my friends. Especially in cakes.

Yes, you always need that pinch of salt in every cake you make, right? So why not just add salted butter? Going for a little bolder flavour? Browned salted butter is what you need in your life. And most definitely you need it in your cakes. Wanna have a test? Go for this sweet potato cake, which has brown butter both in the cake batter and in the frosting. The perfect cake to whip up this upcoming Thanksgiving!

Detail of top ruffles of sweet potato cake with brown butter frosting.

Sweet potato cake with brown butter frosting recipe

This sweet potato cake with brown butter is fairly easy to make, but requires some cooling times here and there. To save on time, I recommend following these steps. Detailed instructions are described below throughout the post.

  • First, take care of the brown butter, to give it time to cool as well as harden;
  • While the butter is cooking, and before it reaches boiling temperature and needs supervision, peel and chop the sweet potato. Then place in the oven to bake;
  • When both the sweet potato mash and brown butter have cooled to room temperature, make the cake batter;
  • While the cake is baking, take care of the frosting.

You can use the fridge or freezer to speed up the cooling times, but keep in mind that these times may vary, so allow some extra time to make sure you’re not using ingredients that are too hot just because you’re in a rush. Make this cake when you have time to devote for it. Quantities are fairly small, and so is the cake (we’re using a 16-cm pan) so it should not take very long overall, anyway.

Frosted sweet potato cake on white cake stand.

Step 1: How to make browned salted butter

First of all, check the amount of salt in your salted butter. In Sweden there are three varieties of butter one can commonly find in supermarkets. The regular butter is generally salted and contains about 1-1,2 g of salt per 100 g. There is also an “extra salted” version that contains 1,8-2 g of salt per 100 g. Definitely less common and not so easy to find in smaller shops is unsalted butter. The butter I used in this recipe is the regular salted butter with a salt content of 1,2%.

Since in this sweet potato cake recipe we’re using brown butter both in the cake batter and the frosting, it is a good idea to start making a batch of brown butter that will serve the whole recipe. Add 175 g of salted butter to a saucepan and set it on medium-high heat. Let the butter melt completely. When it reaches boiling temperature, the surface will get frothy and the water naturally contained in the butter will start to evaporate. From this moment it is wise to keep an eye on the butter and stir it to prevent the proteins from sticking to the bottom of the pan and burning.

Keep stirring (or whisking, I actually prefer using a whisk for this procedure) until you see that the white particles floating in the fat (the milk proteins) on the bottom of the pan have started to turn brown. You can keep track of the temperature with a food thermometer: your brown butter is ready when it reaches 125°C (257°F). When done, immediately transfer the brown butter into a bowl to stop the cooking process, as letting it sit in the hot pan could eventually make it burn. If you don’t have a thermometer, you can tell it’s ready when the milk proteins have turned light brown from white.

Sweet potato cake with brown butter frosting on white cake stand.
In this cake, brown butter is used both inthe frosting and cake batter.

Step 2: Preparing the roasted sweet potato

The other star of the show in this fabulous sweet potato cake with brown butter is obviously the sweet potato. In this recipe we’re using it roasted, as opposed to boiled. Roasting brings out all the sweetness of the sweet potato and perfectly complements the “burnt” tones of the brown butter. We only need 150 g of roasted sweet potato mash in the cake, but if using a large sweet potato I’d recommend to go ahead and roast it all. Leftovers can be frozen for future use or just enjoyed as side dish later in the day!

Peel and chop the sweet potato. Rub some olive oil over its surface and place the bits on an oven tray lined with baking paper. Bake in the oven at 200°C for about 20 minutes or until cooked through. Baking time may vary depending on sweet potato bits size. Let the roasted sweet potato cool to room temperature, then blend until smooth with a hand blender. Separate a half cup (150 g) to use immediately in the cake.

Roasted sweet potato mash in a half cup, cardamom pods around it.

Step 3: Make the cake batter

When both the roasted sweet potato mash and the brown butter have cooled to room temperature, it is time to make the sweet potato cake batter. Combine the eggs and dark muscovado sugar and beat at medium speed for about 2 minutes, or until the mixture is smooth. Muscovado sugar can be lumpy, so make sure to beat the sugar and egg well. Lower the mixer speed and incorporate the sweet potato mash. Then add the liquid brown butter and mix that in. Set the mixer aside, take a silicone spatula and stir in the milk.

Combine the flour and baking powder and sift this powdery mixture into the cake batter. Gently fold in with the spatula. Open the cardamom pods to release the seeds and coarsely grind the seeds in a pestle. Add the cardamom to the cake and fold it in. Transfer the cake batter to a springform pan lined with baking paper and bake in the preheated oven for 45-50 minutes or until a toothpick inserted in the centre comes out clean.

This is a small cake that serves 4-6 people, baked in a 16-cm round cake pan. If you wish to make a larger cake, double up the batter ingredients. If you wish to both fill and top a larger cake with frosting, double the frosting ingredients; otherwise the frosting quantity in this recipe will be enough to just frost the top of the cake, carrot cake style.

Sweet potato cake sliced up to be frosted, frosting on the side.

Step 4: Make the brown butter frosting

The second batch of brown butter should have hardened. Ideally we want to whip it at room temperature, so do not leave it in the fridge overnight if making this recipe over two days. It is okay to harden it in the fridge, though, if you are going to whip it as soon as it hardens.

Beat the hardened brown butter at high speed for about 3 minutes, it should get paler and glossy. Add the cream cheese and powdered sugar and start the mixer again, this time at low speed. Mix until incorporated. You could add some vanilla to the frosting, or even some extra cardamom, but keeping things simple will work just fine and no other flavour will overwhelm the brown butter tones.

Sliced frosted cake, plated slices on the side.

Step 5: Assemble the cake and serve

The amount of frosting we get in this recipe is enough for two layers, so you can cut your cake in half and fill it with half of the frosting, then spread the rest over the top of the cake. Alternatively, you can also go for a classic “carrot cake look”, which is to say a taller cake with the frosting only on the top. If doing so, the frosting layer will be much thicker. I personally think that having a layer of frosting in the middle helps get the combination of flavours at every bite. I also like that it keeps even more moisture in the cake.

This cake will last in the fridge for 3-4 days, but will dry up as the time passes. Since this is a small cake, I’d recommend making it fresh and serving it directly, or after just a few hours of chilling. Serving so few people, it’s unlikely there will be any leftovers, really. A delicious alternative to other classics, something between a sweet potato pie and a carrot cake, this sweet potato cake with brown butter might become your new Thanksgiving favourite!

Sweet potato cake with brown butter frosting.

Frosted sweet potato cake on white cake stand.
5 from 11 votes
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Sweet potato cake with brown butter frosting

A delicious cake for the autumn season, this sweet potato cake with brown butter frosting will surprise you with its deep flavours. An intense brown butter frosting fills and tops a cake made with roasted sweet potato, brown butter and coarsely ground cardamom for an explosion of flavours! A great alternative to carrot cake with cream cheese frosting.

Course Dessert
Cuisine American
Prep Time 1 hour 30 minutes
Cook Time 50 minutes
Total Time 1 hour 50 minutes
Author Eva

Ingredients

  • 175 gr butter
  • 150 gr roasted sweet potato mash (see instructions below)
  • 2 eggs
  • 100 gr muscovado sugar
  • 50 ml milk
  • 150 gr flour
  • 1 tsp baking powder
  • 1 tsp coarsely ground cardamom
  • 200 g cream cheese
  • 80 g powdered sugar

Instructions

Step 1: Roast the sweet potato and mash

  1. Peel and chop the sweet potato. Lightly rub some olive oil over the pieces and lay over an oven tray lined with baking paper. Bake for about 20 minutes at 200°C, or until the sweet potato feels cooked through. When done, let cool to room temperature and blend with a hand blender until smooth. 

    In this recipe we are only using 150 g of sweet potato mash, which equals 1/2 cup. Unless using a fairly small sweet potato, I recommend going ahead and roasting a whole potato, then taking the amount needed for the recipe. Leftovers can be stored in the freezer for future use or enjoyed as side dish to whatever meal you're having after making this cake.

Step 2: Brown the butter

  1. Add 175 g of salted butter to a saucepan and set on medium-high heat. Let the butter melt and reach boiling temperature. Keep cooking it until the white particles in the fat (the milk proteins) turn light brown from white. If using a thermometer, this happens at 125°C. Stir the cooking butter from time to time to prevent the proteins from sticking to the bottom and burning. When the brown butter is ready, immediately transfer it to another container to stop the cooking and prevent it from burning.

  2. Separate 50 g in one container and 90 g in another. The 50 g should cool to room temperature and stay liquid. The 90 g should harden, so you can keep it inthe fridge until you're done with the next steps.

Step 3: Make the sweet potato cake

  1. Combine the eggs and sugar and beat at medium speed for 2-3 minutes. Muscovado sugar can get clumpy, so make sure to get a smooth texture when beating. Lower the speed and add 150 g of sweet potato mash, then 50 g of liquid brown butter. Both need to be at room temperature.

  2. Set the mixer aside and stir in the milk. Combine the flour and baking powder and sift mixture into cake batter, folding it in gently. Lastly, fold in the coarsely ground cardamom.

  3. Transfer batter to a 16 cm springform pan lined with baking paper and bake in the preheated oven at 180°C for 45-50 minutes, or until a toothpick inserted in the centre comes out clean.

Step 4: Make the frosting

  1. Whip the hardened brown butter (90 g) at high speed for about 3 minutes. Add cream cheese and sugar and whip at low speed until incorporated. Chill until the cake has cooled and can be frosted.

Step 5: Frost the cake

  1. When the cake has cooled to room temperature, cut it in half to create two layers. Spread half of the brown butter frosting over the bottom layer, cover with top layer and spread remaining of the frosting over the top. Keep chilled until serving time.

Recipe Notes

This recipe is meant to be baked in a 16-cm round cake pan, and yields about 4-6 portions. If catering to a larger party, double the cake batter ingredients to fill a standard 22-24 cm cake pan.

The frosting quantity in this recipe is enough to fill and top a 16-cm cake. If making a larger cake, the frosting will only be enough for a top layer; double the frosting quantities if you wish to have the frosting both on the top and in between cake layers.

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28 Comments

  1. Jacqui Debono September 25, 2019 at 21:46

    We have so many sweet potatoes coming from the garden – I never thought about making a cake with them! The photos are gorgeous too – will definitely try this on my next baking day!

    Reply
    1. Eva September 27, 2019 at 21:24

      I envy your abundance of sweet potatoes! Enjoy 🙂

      Reply
  2. Anna September 26, 2019 at 09:55

    What a pretty looking cake! I love the use of sweet potatoes there, I’ve made sweet potato brownies before, but never tried adding it to the cake batter, which seems like a genius idea! Looking forward to testing this very soon!

    Reply
    1. Eva September 27, 2019 at 21:25

      Hi Anna! I hope you enjoy this cake. I still have to try sweet potato brownies, instead! Gotta look into that now.

      Reply
  3. Aleta September 27, 2019 at 03:13

    How have I never heard of browned butter yet? I can only imagine how delicious it would be, especially when paired with this gorgeous sweet potato cake! I can’t wait to try this tasty looking recipe!

    Reply
    1. Eva September 27, 2019 at 21:26

      Really? Oh my you’re gonna love it! Definitely make yourself a batch and use it on every possible food, brown butter is the best condiment ever for butter lovers!

      Reply
  4. Maggie Unzueta September 27, 2019 at 18:22

    Oh my word! This cake looks incredible. I haven’t had a sweet potato cake in ages. Gotta make this for my family.

    Reply
    1. Eva September 27, 2019 at 21:27

      Gracias Maggie!!

      Reply
  5. Michelle September 28, 2019 at 16:18

    What a stunning cake. Beautiful flavors for Thanksgiving in this recipe. I’ve never had sweet potatoes in a cake before. I’m sure it makes it moist and a nice subtle sweetness of flavor.

    Reply
    1. Eva October 1, 2019 at 13:12

      Thank you Michelle! It’s definitely a great one for Thanaksgiving!

      Reply
  6. Sam | Ahead of Thyme September 29, 2019 at 05:40

    Wow this cake looks gorgeous! Can’t believe that there is sweet potato in there! Such a great way to use up any extra sweet potatoes. Can’t wait to try this!

    Reply
    1. Eva October 1, 2019 at 13:14

      Definitely a good way to sneak sweet potato into someone’s diet 🙂

      Reply
  7. Anne Lawton September 29, 2019 at 20:02

    I have to jump on that brown butter bandwagon for sure! This cake looks absolutely amazing

    Reply
    1. Eva October 1, 2019 at 13:15

      Please do! You need brown butter in your life!

      Reply
  8. SHANIKA September 29, 2019 at 20:38

    Sweet Potato Cake is right up my alley! This cake looks so fluffy and moist! And I’m loving the addition of brown butter frosting!

    Reply
    1. Eva October 1, 2019 at 13:15

      Brown butter in the frosting just elevates the whole thing!

      Reply
  9. Kushigalu September 29, 2019 at 23:09

    What a gorgeous cake and lovely frosting. I will try this soon for my lil ones birthday. Thanks for sharing

    Reply
    1. Eva October 1, 2019 at 13:16

      You’re welcome! Hope your little one approves!

      Reply
  10. Debbie September 30, 2019 at 04:02

    Wow, what a BEAUTIFUL sweet potato cake , I love the addition of cardamom and that you roast and mash your own potatoes. This fresh cake sounds out of this world and there is nothing better than rick browned butter frosting . This on my fall must try list !!

    Reply
    1. Eva October 1, 2019 at 13:17

      Thanks Debbie! I hope you will enjoy it as much as I do!

      Reply
  11. Julia Kirk October 4, 2019 at 03:25

    Beautiful presentation! with healthy roasted sweet potatoes to make me feel good about eating this delicious cake.

    Reply
    1. Eva October 11, 2019 at 15:30

      Thank you Julia! Yes, the health factor surely helps feel less guilty about this scrumptious cake!

      Reply
  12. Priya Iyer October 18, 2019 at 09:25

    Wow, the cake looks absolutely stunning! In India, we use sweet potato in curries and chaat, but I have never seen it used like this in a cake. Such a lovely recipe! 🙂

    Reply
    1. Eva October 21, 2019 at 14:00

      Sweet potato is such a versatile ingredient, goes great in both sweet and savoury dishes!

      Reply
  13. Sally - My Custard Pie October 28, 2019 at 11:37

    What a great idea to use pumpkin in a cake – a change from carrot

    Reply
    1. Eva November 2, 2019 at 09:25

      Thank you Sally. Yes, that was my thought, I wanted something similar but different.

      Reply
  14. Sally Pederson October 29, 2019 at 16:22

    That looks delicious. I’m going to have to try to make that one day.

    Reply
    1. Eva November 2, 2019 at 10:23

      Thanks Sally! Hope you enjoy 🙂

      Reply

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