1 cup (2 sticks) unsalted butter
3/4 cup (1.5 ounces) mini marshmallows
2 ounces unsweetened chocolate, chopped (You need to do this in a food processor or chopper, y'all. Unsweetened chocolate is HARD.)
1 cup Coca-Cola, NOT DIET!
2 1/3 cup (12 ounces) all purpose flour
3/4 cup cocoa powder
1.5 teaspoons baking powder
1 teaspoons baking soda
1/2 teaspoon salt
2 cups sugar
1/2 cup vegetable or canola oil
2 teaspoons vanilla extract
3 extra large eggs
3/4 cup buttermilk
2 cups (4 sticks) salted butter, softened (I always use salted butter in a buttercream because it cuts the sweetness a bit.)
1/2 cup Coca-Cola, Once again NOT DIET!
1/2 teaspoon vanilla extract
1 cup cocoa powder, SIFTED!
4 ounces unsweetened chocolate, chopped then melted (in microwave)
1.25 pound powdered sugar, SIFTED! (Keeps your icing from being lumpy.)
Preheat oven to 325 degree F.
To prepare cake, melt butter in a 2 quart bowl in the microwave. (When microwaving butter, do it in one minute increments. Stirring often. There will still appear to be solid pieces and suddenly you will stir and it will all be melted.)
Add marshmallows and microwave in one minute increments. Stirring each time the microwave stops. Do this until melted.
Added the chopped chocolate and repeat microwaving and stirring until it has melted into the mixture. Stir in the Coca-Cola then set aside and let cool for 10 minutes.
Sift flour, cocoa powder, baking powder, baking soda, and salt.
Place sugar, oil, and vanilla in a large mixing bowl or in the bowl of your KitchenAid mixer. Beat on medium speed. Add eggs one at a time, beating well after each addition.
Add cooled chocolate mixture and beat on low until combined. Add half the flour mixture, then the buttermilk, then the remaining flour mixture. Scrape down the sides after each addition.
Scrape into 2 (9-inch) cake pans. Bake 40 to 45 minutes until cake springs back when lightly touched. Let cool for 15 minutes and remove from pans. Let cool completely.
Cream softened butter in a bowl using a mixer until smooth. Add vanilla and mix on low speed until blended.
Gradually add cocoa powder and chocolate, alternating with Coca-Cola and mixing on low speed until well blended and smooth, scraping down the sides often.
Beat in powdered sugar, 1/2 cup at a time on low speed. Beat until smooth. Best if made one day ahead of when needed and kept at room temperature.
Frost cake and serve. (I always wrap layers separately in plastic wrap and freeze for at least 2 hours before frosting to make it easier and less crumby.)