The surprise inside this pumpkin cake is a swirl of chocolate. Use your measuring cup to mix the chocolate into the batter so you don't have to wash another bowl. Pumpkin-Chocolate Swirl Cake with Chocolate Ganache Ingredients Cake 1 box Betty Crocker™ SuperMoist™ spice cake mix 1 cup canned pumpkin (not pumpkin pie mix) 1/2