Put the flour, baking powder, and cocoa powder into a sieve. Sieve into a bowl and make sure to break down any lumps.
2 cups all-purpose flour, 2 tsp baking powder, 2 tbsp cocoa
Add the remaining ingredients for the cake base into the bowl.
1 cup sugar, 1 egg, 150 grams (5oz) butter
Mix with your hands or a hand mixer until all the ingredients are well combined.
The texture should resemble a crumble mixture.
Put 2/3 of the dough into a greased 9inch springform pan.
Put the remaining 1/3 of the dough aside for later.
Spread the dough out using your fingertips. You can also use a glass with a flat bottom.
Press the dough down evenly and also around the edges.
Put the springform pan into the fridge while you are preparing the filling.