Chocolate cake mix plus the ingredients on the box to make ittypically 3 eggs, 1/3 cup oil, 1 cup water
Preheat the oven 350º F. Lightly grease a 9x13 inch pan.
Prepare the chocolate cake mix according to the instructions. Most likely the recipe will call for 3 eggs, 1/3 cup oil, and 1 cup water. Pour the cake mix into the pan.
In a separate bowl mix together the pumpkin puree, eggs, evaporated milk, pumpkin spice extract, cinnamon, nutmeg, cloves, and brown sugar until smooth.
Evenly pour the pumpkin mixture over the chocolate cake mixture.
Bake the cake for 55-65 minutes or until a toothpick inserted in the center comes out clean.
Allow the cake to cool to room temperature before serving. You can also refrigerator the cake over night and serve it cold. Cut and serve the cake, top each piece with a dollop of cool whip before serving. Dust with cocoa powder, optional.