Peanut Butter Meltaway Cake

1/4 Cup Buttermilk

1/4 Cup Cocoa

2 Eggs -- Beaten

1 Cup Water

1 Cup Margarine

2 Cups Sugar

2 Cups Flour

1 Teaspoon Baking Soda

1 Teaspoon Vanilla

1 Cup Peanut Butter

1 Tablespoon Salad Oil

1/2 Cup Margarine

1/4 Cup Cocoa

1 Pound Powdered Sugar

6 Tablespoons Buttermilk

1 Teaspoon Vanilla

Mix together 1/4 cup buttermilk, 1/4 cup cocoa, eggs, water and 1 cup margarine. Add in sugar, flour, baking soda and vanilla. Beat until smooth. Grease and flour a 9x13-inch baking pan. Bake at 350 degrees for 25 minutes. Let cool. Mix together the peanut butter and salad oil. Spread over cooled cake. Refrigerate for 20 minutes. Heat 1/4 cup cocoa and 1/2 cup margarine. Stir until it bubbles. Add powdered sugar, 6 tablespoons buttermilk and vanilla. Beat until smooth and spread over cake.