Marbled Pumpkin Chocolate Brownies

Preheat oven to 180 C / Gas 4. Grease an 20x20cm baking tin. Stir the flour, baking powder and salt together in a bowl.

In another bowl, stir together the melted butter, sugar and vanilla extract; beat in the eggs one at a time with a spoon. Gradually add the flour mixture and stir the batter until it is evenly moistened. Divide the batter in half in two separate bowls.

Into one bowl of batter, blend the cocoa powder and chocolate chips. In the second bowl of batter, stir in the pumpkin puree, walnuts, cinnamon, cloves and nutmeg.

Spread 1/2 of the chocolate batter into the bottom of the prepared baking tin and follow with 1/2 of the pumpkin batter. Repeat the layers, ending with a pumpkin layer and drag a kitchen knife or small spatula gently through the layers in a swirling motion, to create a marbled effect.

Bake in the preheated oven until the brownies begin to pull away from the sides of the tin and a skewer inserted into the centre comes out clean, 40 to 45 minutes. Cool in the tin, cut into squares and serve.