Step 1

To make the cake, preheat the oven to 350 degrees Fahrenheit. Grease a 9x13-inch pan with oil or butter.

Step 2

Sift the flour, sugar, and baking soda into a large bowl. Set aside.

Step 3

Boil 1 cup of butter, 3 tablespoons of cocoa powder, and 1 cup of Coca Cola. Pour mixture over the dry ingredients and mix until lump-free.

Step 4

Stir in the buttermilk, eggs, vanilla, and mini-marshmallows until well-combined.

Step 5

Pour the batter into greased pan and bake for 40 minutes, or until a toothpick inserted into the center comes out clean or with a few dry crumbs. Let cake cool on a wire rack.

Step 6

While the cake is in the oven, prepare the frosting. Combine 1/2 cup of butter, 2 tablespoons cocoa powder, and 6 tablespoons of Coca-Cola in a saucepan. Cook over medium heat, stirring constantly until it boils.

Step 7

Remove from heat and beat in the powdered sugar until the mixture is smooth. Add the chopped pecans and spread evenly over the warm cake. Let it cool completely before slicing. Enjoy!