Cooking oil spray, to grease
60 g butter
¾ cup caster sugar
⅓ cup water
3 eggs, lightly beaten
¼ cup canola oil
1 tsp vanilla extract
1¼ cups plain flour
1 tsp baking powder
¼ cup creamy peanut butter
¼ cup milk
½ cup unsweetened cocoa powder
¼ cup dark chocolate baking bits
- Preheat oven to 180°C. Grease a 26 x 16 x 5cm slice tin. Line with baking paper, extending paper over edges of tin, and set aside.
- Put butter in a medium saucepan over a low heat until melted. Remove from heat. Stir in sugar and water until sugar is dissolved. Stir in eggs, oil and vanilla. Stir in 1 cup of the flour and baking powder until combined (batter will be thin).
- Put ½ cup of batter into a small bowl; whisk in peanut butter and 1 tablespoon of the milk until smooth. Using a separate small bowl, combine remaining ¼ cup flour and cocoa powder. Stir flour mixture and remaining 2 tablespoons milk into remaining batter; stir in chocolate pieces.
- Pour chocolate batter into prepared tin. Spoon peanut butter batter in small mounds onto chocolate batter. Using a table knife or narrow metal spatula, swirl batters slightly to marble.
- Bake for 20-25 minutes or until top springs back when lightly touched and a skewer inserted in the centre comes out clean. Cool in tin on a wire rack. Using the edges of the baking paper, lift from the tin, cut into squares and serve.