- In a large bowl, mix the butter and caster sugar with a spoon until fluffy, or use an electric mixer.
- Add the eggs, orange extract, and milk. Whisk until fully incorporated.
- Add the self-raising flour, cocoa powder, and baking powder. Whisk until the batter is smooth and you can't see any flour.
- Divide the mixture evenly between the prepared tins. Use scales for accuracy.
- Bake for 30-35 minutes or until a skewer inserted in the middle comes out clean.
- Leave the cakes to cool completely, either in the tins or on cooling racks after removing them from the tins.