In Detroit in 1912, after many years of success and prominence in the chocolate, candy and ice cream business, Fred Sanders decided it was time to pay homage to his baker father who had passed away years earlier. Fred, remembering his father’s fondness for chocolate devil’s food cake, paired this traditional dessert with his confection expertise. After many attempts and long hours, Fred perfected one of our most legendary and original confections, the Chocolate Bumpy ™ Cake by combining chocolate devil’s food cake with buttercream ridges, and then pouring a rich chocolate fudgy ganache over the entire baked dessert. The “bumpy ridges” were a happy accident put on the cake after Fred was running short of buttercream on one of his many test runs. Fred decided to put on four ridges and everyone loved the idea. Unfortunately Fred “Grandpa” Sanders died before he saw his creation become an American favorite.
For me, this cake just looked like a great big Yodel and I decided to give it a shot. OMG. This was a lot of work. First you make the chocolate cake. Then the buttercream. Then the chocolate ganache. But there was a lot of freezing and waiting and I was exhausted by the time I finally got it in the fridge for the night. If you decide to make it, be patient!!
For the Cake:
1 tablespoon unsalted butter
1/2 cup plus 2 tablespoons unsweetened Dutch process cocoa powder
1/2 cup hot black coffee
1/2 cup canola oil
1 cup buttermilk
1 tablespoon pure vanilla extract
1 1/2 teaspoons baking soda
1/2 teaspoon salt
2 eggs, lightly beaten
3/4 cup dark brown sugar, firmly packed
3/4 cup white sugar
2 cups all-purpose flour
For the Buttercream Frosting
1/4 cup unsalted butter
1/4 cup vegetable shortening
2 1/2 cups confectioners sugar
1 teaspoon vanilla extract
For the Pourable Fudge Frosting
1/2 cup buttermilk, room temperature
2 1/2 cups powdered sugar
1 teaspoon vanilla extract
1 cup sugar
1/3 cup unsweetened Dutch process cocoa powder
1/3 cup dark corn syrup
1/4 teaspoon salt
16 tablespoons (2 sticks) unsalted butter, cut into tablespoon-sized pieces
Set oven rack to the middle position and preheat oven to 375°F. Grease a 9- by 13-inch pan or baking dish with butter. Add 2 tablespoons cocoa powder to pan and shake and tap pan gently until the butter is completely coated in cocoa. Tip out excess.
FOR THE CAKE:
In the bowl of a stand mixer, combine cocoa and coffee, beat on medium speed for 30 seconds. Add oil, beat for 30 seconds; add buttermilk, beat for 30 seconds; add baking soda, beat for 30 seconds; add salt, beat for 30 seconds; add vanilla, beat for 30 seconds; add eggs, beat for 30 seconds; add sugars, beat for 30 seconds. Add flour and beat about 5 minutes to remove any lumps. Batter may begin to bubble.
Pour batter into prepared pan and use spatula to smooth top. Bake until cake tester comes out clean, 35 to 40 minutes. Transfer to a rack and allow to cool for at least 30 minutes. Transfer to the freezer for at least an hour and up to overnight.
FOR THE BUTTERCREAM BUMPS:
In the bowl of a stand mixer fitted with a paddle attachment, cream together butter and shortening on medium speed until light and fluffy, about 3 minutes. Add confectioners’ sugar and mix to fully incorporate, about 1 minute. Add vanilla extract and mix until blended, about 30 seconds. Transfer frosting to a piping bag with no tip. Tie a rubberband around the end. Refrigerate for at least 15 minutes to firm up frosting.
Pipe frosting crosswise into seven 1-inch wide lines spaced 1-inch apart (each "bump" should run the length of the cake, 9-inches long). Return cake to the freezer for at least 30 minutes to set the frosting. (The above picture I got the lines going the wrong way so I changed it in the picture below. The bumps should run the long side of the pan, not like above.
FOR THE FUDGE TOPPING:
SIDE NOTE: I SHOULD HAVE WAITED ANOTHER MINUTE FOR THE FUDGE TO COOL. THIS WOULD HAVE ALLOWED THE BUMPS TO BE COMPLETELY COVERED. ((I didn't have a thermometer!!!))
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).
Remove frosted cake from freezer and pour cooled frosting over the cake in long strokes to cover buttercream rolls completely. Note: frosting will be thin and sauce like. Working quickly and evenly you'll be able to completely cover the bumps with a thin layer of frosting, while "frosting runoff" will create fudgy pockets along the surface beside the bumps that will firm up in the freezer. Return cake to freezer for at least 30 minutes more to set. A smaller, paring knife is most effective for cutting while maintaining the cake's unique look. Serve chilled and store leftovers in refrigerator or freezer.