If you are not from Michigan, you may never have heard of Bumpy Cake. Bumpy Cake is basically a cake, with piped buttercream frosting over the top and then covered with a fudge ganache. It is a fun cake to make and a very fun cake to eat. I made my own homemade chocolate cake, but you can save a little time and use a mix if you prefer. Here in Michigan, they tend to come with vanilla buttercream, but I love the hit of Peanut butter in this version! I like to make this cake in two square pans as opposed to one 13×9 cake pan. This allows me to freeze one of the cakes for a quick dessert in the future.
To freeze, just cover one of the chilled cakes in it’s pan well witch plastic wrap and then cover again with foil and pop it into the freezer. When you are in need of a quick, impressive dessert – just pull that bad boy out of the freezer and let it thaw on the counter for about an hour. Joy. I made this recipe for a co-worker’s birthday and my family got to eat the second one. Score! Two wins!
Here are the basics:
Bake the cakes in two square or one rectangular cake pan. While the cake is baking, make the peanut butter buttercream and the fudge ganache. After the cake is cool, pipe the buttercream over the top of the cake. Put them into the freezer for an hour after to let the buttercream set so the fudge frosting does not ruin the bumpy effect.
Then just pour the fudge ganache over the top and let it set in the freezer for one hour.
It will get firm as it cools. This cake actually gets better as it sits. Making it the day before and popping in the fridge works very well.
So, Let’s get to the recipe!
Chocolate Peanut Butter Bumpy Cake
(Makes one large 9×13 inch cake or two 8×8 in cakes.
2 c. sugar
4 tsp. vanilla
1 1/4 c. oil
1 c. cocoa
2 and 1/3 c. flour
1 1/4 tsp. baking soda
1 1/4 tsp. baking powder
1 tsp. salt
1/4 teaspoon salt16 tablespoons (2 sticks) unsalted butter, cut into tablespoon-sized pieces
In a large bowl whisk together buttermilk, confectioner’s sugar and vanilla and set aside. In a medium saucepan, combine, sugar, cocoa, corn syrup, salt and 1 stick worth of butter. Stir occasionally to fully incorporate butter as it’s melting then bring mixture to a boil over medium high heat. Cook until mixture registers 240°F on a candy or instant read thermometer (a small amount dropped into cold water should form a soft, malleable ball), then remove from heat. While whisking constantly, add hot mixture to buttermilk mixture. Add remaining butter pieces and continue whisking until fully incorporated and mixture has cooled (frosting must be only slightly warm).
Pull the cakes from the freezer and pour the slightly warm frosting over the tops of the cakes evenly and quickly, making sure to cover the entire surface.
When finished put cakes in the freezer for 1 more hour to set the frosting. This cake tastes best served chilled, it can be eaten right away, or refrigerated and served another day. Leftovers can be frozen easily and the cake is just as good thawed as fresh.