the cake:
1 cup unsalted butter
4 ounces mini marshmallows
4 tablespoons cocoa powder
1 cup Dr. Pepper
2 cup all purpose flour
1 teaspoon baking soda
½ teaspoon salt
2 cups sugar
2 eggs
1½ cups buttermilk
1 teaspoon vanilla
Preheat oven to 350ºF. Lightly butter and flour a standard half sheet pan (a 9x13-inch pan works as well.)
In a saucepan over low heat, melt the butter, marshmallows, cocoa powder and Dr. Pepper. Set aside and let cool slightly. In a large bowl, whisk together the flour, baking soda, salt and sugar. Make a well in the center of the dry ingredients and pour the wet ingredients into the dry. Stir together gently with a rubber spatula just to combine. In a small bowl, whisk the eggs, buttermilk and vanilla together. Add to the chocolate batter and mix until just combined.
Pour the batter into prepared sheet pan. Bake for 20 minutes, rotating the pan halfway through to ensure even baking. The cake should spring back when touched in the center. Cool on a wire rack.
For the icing:
1 cup butter
6 tablespoons Dr. Pepper
4 tablespoons cocoa powder
1 teaspoon vanilla
3/4 pound sifted powdered sugar
1 cup chopped pecans, toasted (optional)
In a medium sauce pan, heat the butter, Dr. Pepper, cocoa powder and vanilla until barely simmering. Take the pan off stove and whisk in the powdered sugar. Stir in the pecans. Pour the still-warm icing over the cake immediately. (If icing has cooled and set a bit, you can rewarm over a low flame if necessary.)
n.b. My alternative to the pecans was toffee bits, sprinkled on top of the icing right before serving
