CAKE:

2 c. flour
2 c. sugar
1 tsp. baking soda
1 c. butter
1 c. water
1/4 c. cocoa powder
2 eggs
1/2 c. buttermilk
1 tsp. vanilla

FROSTING:

1/3 c. butter
1/4 c. buttermilk
3 tbsp. cocoa powder
3 1/2 c. sifted powdered sugar
1 tsp. vanilla

FILLING:

1 1/2 c. peanut butter
1 tbsp. peanut or cooking oil

For Cake: Combine flour, sugar and soda in a mixing bowl; then set aside. Bring butter, water and cocoa to a boiling and remove from heat. Add chocolate mixture to dry ingredients and beat with mixer until thoroughly combined. Add eggs, buttermilk and vanilla. Beat well. Pour batter into a greased and floured pan. Bake at 350 degrees for 25-35 minutes. Cool completely on wire rack.

For Filling: Stir together peanut butter and oil. Spread over cake. Let filling set before frosting.

For Frosting: Combine butter, buttermilk and cocoa powder in a medium saucepan. Bring to a boil and remove from heat. Add to powdered sugar with vanilla. Beat until smooth.