Prick the sweet potatoes with a fork and place on an oven tray lined with baking paper. Roast at 200C (392F) until tender, depending on the size of the potatoes this could take from 40 minutes up to an hour. Let cool completely.
Press shortcrust dough onto a tart pan. Prick the bottom and sides with a fork. Cool in the freezer for 15 minutes and bake in the preheated oven at 180C (356F) for 20-25 minutes, until golden. Let cool on a wire rack.
Remove the skin from the sweet potatoes. Aside, melt 200 g chocolate, then add it to the sweet potatoes. Add 3 tablespoon maple syrup. Blend with a hand blender until smooth.
Pour sweet potato mixture onto cooled baked tart shell, spreading it out to evenly cover the whole bottom all the way to the edges.
Add remaining chocolate and coconut oil to a bowl and melt in the microwave. Add 1 tablespoon maple syrup and stir to incorporate. Pour over pie filling and spread out evenly.
Notes
The nutritional information shared here is obtained using an online calculator and therefore only to be used as a guideline.
Roast the sweet potatoes ahead to reduce total time. If you roast the sweet potatoes on the same day, you could bake the shortcrust shell as the potatoes are roasting. Since the temperature is a tad higher, factor in a shorter baking time. The use of a convection oven is recommended, if planning to bake at the same time.