Combine the eggs, flour, milk, granulated sugar, cocoa powder and vegetable oil in a blender and mix until homogeneous.
Warm a crepe pan and when hot pour in a ladleful of crepe batter. Cook on medium-high heat until the top looks set and the edges of the crepe naturally peel off the pan (about 2 minutes). Gently slide a spatula under the crepe and flip it over. Cook the other side for just about a half minute. Repeat until all of the batter has been used.
Let crepes cool completely before moving on to the next step. If making ahead, stack them on a plate, cover with cling film and keep refrigerated.
Optionally you can trim the edges of the crepes. Find a plate the desired size, place it on top of each crepe and run a knife around the edges. This is not an obigatory step, but helps achieve more regular edges to your cake.
Combine 500 ml of whipping cream with the powdered sugar and whip to hard peaks.
Finely mince about half of the drained sour cherries.
Place a crepe on a cake stand. Spread a thin layer of whipped cream on a crepe using an angled spatula, then add some minced cherries on top. Stack the next crepe on top and proceed working this way. Remember that the last crepe should have no frosting over it.
Place the cake in the fridge to set as you prepare the ganache.
Warm the remaining cream in a double boiler or in the microwave. When hot stir in the chocolate chips until dissolved. Let cool for a couple of minutes.
Take the cake out of the fridge and place it over a rack. Pour the ganache in a slow stream allowing it to pour over the edges of the top layer and down the sides of the cake.
Before the ganache hardens, add remaining cherries on the top as decoration. Chill in the fridge for a minimum of 1 hour before serving.