-
Prepare the Cake
-
Preheat oven to 350°F (175°C).
-
Grease and line a 9×13-inch baking pan.
-
In a bowl, whisk together flour, cocoa powder, sugar, baking soda, and salt.
-
Add egg, buttermilk, oil, and vanilla, mixing until smooth.
-
Slowly pour in hot coffee while stirring until the batter is thin.
-
Bake
-
Pour batter into the prepared pan.
-
Bake 25–30 minutes, or until a toothpick inserted in the center comes out clean.
-
Let the cake cool completely in the pan.
-
Make the Buttercream Filling
-
Beat butter until creamy.
-
Add powdered sugar and vanilla, mixing until fluffy.
-
Add heavy cream gradually until smooth and pipeable.
-
Create the Signature “Bumps”
-
Transfer buttercream to a piping bag with a round tip.
-
Pipe thick lines (bumps) across the cake lengthwise.
-
Place cake in the refrigerator for 20–30 minutes to firm up the frosting.
-
Prepare the Chocolate Topping
-
Heat heavy cream until hot but not boiling.
-
Pour over chocolate chips and let sit 1 minute.
-
Stir until smooth and glossy.
-
Mix in corn syrup if using.
-
Finish the Cake
-
Pour chocolate topping over the cake.
-
Spread gently so the frosting bumps remain visible underneath.
-
Chill 30–60 minutes until the topping sets.