Coca-Cola Cake

My sister made this yesterday for our Memorial Day cookout - very very yummy!

For the cake:
2 cups granulated sugar
2 cups all-purpose flour
1 1/2 cups mini-marshmallows
1/2 cup (1 stick) butter or margarine
1/2 cup vegetable oil
3 tablespoons unsweetened cocoa
1 cup Coca-Cola
1 teaspoon baking soda
1/2 cup buttermilk
2 eggs
1 teaspoon vanilla extract

For the frosting:
1/2 cup (1 stick) butter
3 tablespoons unsweetened cocoa
6 tablespoons Coca-Cola
1 (16-ounce) box confectioners’ sugar
1 teaspoon vanilla extract
1 cup chopped pecans

To make the cake: Preheat oven to 350 degrees. In a bowl, sift together sugar and flour. Add marshmallows. In saucepan, mix butter, oil, cocoa and cola. Bring to a boil and pour over dry ingredients; blend well. Dissolve baking soda in buttermilk just before adding to batter along with eggs and vanilla extract, mixing well. Pour into a well-greased 9-by-13-inch pan and bake 35 to 45 minutes. Remove from oven and frost immediately.

To make the frosting: Combine butter, cocoa and cola in a saucepan. Bring to a boil and pour over confectioners’ sugar, blending well. Add vanilla extract and pecans. Spread over hot cake. When cool, cut into squares and serve.