Bake:
Bake for 18-20 minutes, or until the top is golden brown and a toothpick inserted into the edge comes out clean.
Cool and serve:
Let cool for 10 minutes before serving, warm, so that the chocolate in the centre remains melted. Buttercream
How to make (step summary)
Mix dry and wet ingredients separately.
Mix until smooth.
Separate one portion and mix in cocoa powder.
Layer vanilla and chocolate batter with a chocolate square inside. Bake until puffed and golden brown.
