DETROIT BUMPY CAKE
Ingredients
For the Cake:
1 Tbsp 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 1/2 tsp baking soda
1/2 tsp salt
1 Tbsp pure vanilla extract
2 large eggs, lightly beaten
3/4 cup dark brown sugar,
firmly packed
3/ cup white sugar
2 cups all-purpose flour
For the Buttercream
Frosting:
1/4 cup unsalted butter
1/4 cup vegetable shortening
2 /2 cups confectioners'
sugar
1 tsp vanilla extract
For the Pourable Fudge
Frosting:
1/2 cup buttermilk, room
temperature
2 1/2 cups confectioners'
sugar
1 tsp vanilla extract
1 cup sugar
1/3 cup unsweetened Dutch
process cocoa powder
1/3 cup dark corn syrup
1/ tsp salt
16 Tbsp (2 sticks) unsalted
butter, cut into tablespoon-sized pieces
Directions
1. Set oven rack to the
middle position and preheat oven to 375°F (190°C). Grease a 9- by 13-inch pan
or baking dish with butter. Add 2 tablespoons cocoa powder to pan; shake and
tap pan gently until the butter is completely coated in cocoa. Tip out excess.
2. In the bowl of a
stand mixer, combine 1/2 cup 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.
3. 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.
4. For the Buttercream: 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 fitted with a
large round tip. Refrigerate for at least 15 minutes to firm up frosting.
7. Cook until mixture registered 240 F (116 C) on a candy or instant-read thermometer (tip: A small amount dropped into cold water should form a soft, malleable ball). Remove from heat. While whisking constantly, add hot mixture to buttermilk mixture. Add remaining butter pieces and continue whisking until fully mixed, and it has cooled (frosting must be only SLIGHTLY warm).
8. Remove frosted cake from freezer. Pour cooled frosting over the cake in long strokes to cover the buttercream rolls completely. NOTE: Frosting will be thin & saucelike. Working quickly and evenly, the '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 to set. A smaller paring knife works best for cutting pieces, while keeping the cake's unique bumpy look.
Chill leftover and store leftover in the refrigerator or freezer.
Alexandra Penfold, Detriot Bumpy cake (Chocolate w. Vanilla Buttercream and Chocolate Fudge) Recipe, Serious Eats, Aug. 29,2023.
