2 cups sugar
2 cups all-purpose flour
1 1/2 cups small marshmallows
1/2 cup butter or margarine
1/2 cup vegetable oil
3 tablespoons cocoa
1 cup Coca-Cola®
1 teaspoon baking soda
1/2 cup buttermilk
2 eggs
1 teaspoon vanilla extract

Preheat oven to 350°F.
In a bowl, sift the sugar and flour.
Add marshmallows.
In a saucepan, mix the butter, oil, cocoa and Coca-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.

Frosting:
1/2 cup butter
3 tablespoons cocoa
6 tablespoons Coca-Cola
1 box (16 ounces) confectioners' sugar
1 teaspoon vanilla extract
1 cup chopped pecans

Combine butter, cocoa and Coca-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.