I used a chocolate cake mix. I bet a spice cake mix would be really good too. I didn't ice ours, but it would have been fantastic with whipped cream!
2 Ingredient Chocolate Cake
1 box of cake mix
1 (15 oz) can of plain pumpkin (not pumpkin pie)
A few tablespoons of water, if needed
Preheat oven to 350. Grease a 13x9 inch baking dish.
Mix cake mix and pumpkin. It will be REALLY thick, but if it's not mixing well, add 1 tablespoon of water at a time until moist.
Pour and smooth evenly into pan.
Bake for 20 minutes.