1 c. Coca-Cola
1/2 c. buttermilk
1 c. butter, softened
1 3/4 c. sugar
2 large eggs, lightly beaten
2 tsp. vanilla extract
2 c. all-purpose flour
1/4 c. cocoa
1 tsp. baking soda
1 1/2 c. miniature marshmallows
3/4 c. pecans, chopped and toasted (for garnish)

Combine Coca-Cola and buttermilk; set aside. Beat butter at low speed with an electric mixer until creamy. Gradually add sugar; beat until blended. Add eggs and vanilla; beat at low speed until blended. Combine flour, cocoa and soda. Add to butter mixture alternately with cola mixture; begin and end with flour mixture. Beat at low speed just until blended. Stir in marshmallows. Pour batter into a greased and floured 9 x 13 x 2-inch pan.

Bake at 350°F for 30 to 35 minutes. Remove from oven; cool 10 minutes. Pour Coca-Cola Frosting over warm cake; garnish, if desired.

Coca-Cola Frosting:

1/2 c. butter
1/3 c. Coca-Cola
3 tbsp. cocoa
1 (16 oz.) box powdered sugar
1 tbsp. vanilla extract

Bring first 3 ingredients to a boil in a large saucepan over medium heat, stirring until butter melts. Remove from heat; whisk in sugar and vanilla. Pour over warm cake.