Step 1

Preheat oven to 350° F°. Coat a 9×13 baking dish with baking spray. Set aside.

Step 2

Combine the Dr. Pepper, oil, butter and cocoa powder in a large saucepan over medium heat. When it comes to a simmer, mix well and remove from heat.

Step 3

Whisk the sugar, flour, and baking soda together in a large bowl. Add the dry mixture into the saucepan and stir until combined with a rubber spatula or wooden spoon.

Step 4

In a separate small bowl lightly beat the eggs and buttermilk together. Add the buttermilk mixture into the saucepan and stir until combined and smooth.

Step 5

Pour batter into the prepared pan and bake for 23-28 minutes or until toothpick inserted into the center of the cake comes out clean.

Step 6

In a medium saucepan, combine butter, cocoa powder and milk together over medium heat, stirring occasionally until melted and smooth.

Step 7

Whisk in the powdered sugar a little at a time, combining after each addition until smooth.

Step 8

Pour over warm cake.

Step 9

Serve warm or at room temperature.