This is a traditional and original recipe for Surabaya Layer Cake, a famous old-time cake from Indonesia. It uses lots of eggs and butter, making it very moist and soft!
In a mixing bowl, mix the egg yolk, whole eggs, and powdered sugar with low speed, gradually to high speed for 10-15 minutes.
The batter should be pale and thick. Pour in the dry ingredients: corn starch, milk powder, cake flour. Sieve the dry ingredients first.
Prepare the butter in room temperature. When it softens, mix it with low speed for a while, gradually turn it up to high speed until pale and light.
Mix the butter into the egg mixture with a spatula. Fold the batter and make sure you see the pale butter blend well with the egg batter.
Once you are done mixing and folding, divide the whole batter into 3 parts.
Keep 2 parts as they are (yellow), put in cocoa powder and 1 tsp of chocolate paste in the other one. Mix well.
Pour the batter in the greased 24x24 cm pan, already lined with baking paper.
Bake in the preheated oven 180°C for 20 minutes.
Take out the pan from the oven, and take out the cake from the pan. Let it cool on the cooling rack.
Spread some jam on one side of the yellow cake and 2 sides on the chocolate cake. Assemble the cake together, yellow, chocolate, yellow accordingly.
Let the cake set for an hour at least. You can slice the cake and wrap each slices with a nice packaging. Enjoy!
Video
Notes
Let the cake settle, the next day the cake gets moister and it will be more delicious.
When mixing the butter mixture and the egg mixture, you need to fold very swiftly. Not too fast and not too slow, either. You can use spatula or a whisk.
Remember to beat the egg mixture until pale and light. Check if it leaves trail. It will be around 10-15 minutes, to be safe.