Cooking oil spray, to grease
250 g unsalted butter, chopped
2 cups caster sugar
4 eggs, lightly beaten
2 tsp vanilla extract
1½ cups plain flour, sifted
¾ cup Dutch processed cocoa, sifted plus extra to serve
200 g dark cooking chocolate, chopped
- Preheat oven to 180°C. Grease a 25 x 16cm slice tin and line base and sides with baking paper. Melt butter in a medium heavy-based saucepan over a low heat. Add sugar and stir to combine.
- Set tin aside for 5 minutes to cool slightly. Add eggs and vanilla, and stir to combine. Add flour, cocoa and chocolate; stir to combine.
- Spoon mixture into prepared tin and smooth top. Bake for 30-35 minutes or until top forms a crust. Stand tin on a wire rack to cool. Dust with extra cocoa and cut into squares. Serve.