Preheat oven to 350 degrees F and grease an 8x8 inch baking dish
In a bowl, stir together the flour, baking powder, and salt. In a separate bowl, stir together the melted butter, vegetable oil, sugar, and vanilla extract. Beat in the eggs one at a time using an electric hand mixer or spoon
Gradually add the flour mixture and stir together until the batter is evenly moistened and combined
Divide the batter in two separate bowls, leaving slightly more batter in one bowl. In the bowl with more batter, stir in the cocoa powder and chocolate chips until combined. In the second bowl with less batter, stir in the pumpkin, cinnamon, cloves and nutmeg until combined
Pour the chocolate batter into prepared pan and spread evenly. Pour pumpkin batter over the chocolate batter and spread evenly
Bake in the preheated oven until toothpick inserted into the center comes out clean, 35-40 minutes. Cool in pan, cut into squares, and serve