- 3 cups all-purpose flour
 - 2 teaspoons baking soda
 - 1 teaspoon salt
 - 6 tablespoons unsweetened cocoa powder
 - 2 cups white sugar
 - 10 tablespoons butter, melted
 - 2 teaspoons distilled white vinegar
 - 2 cups warm water
 - 1/4 cup peanut butter
 - 1 cup packed brown sugar
 - 1/4 cup milk
 - 1/4 cup butter, softened
 
- In a large bowl, sift together the flour, baking soda, salt, cocoa, and white sugar.
 - To the sifted ingredients, add the 10 tablespoons butter or margarine, vinegar, and warm water. Mix thoroughly, but do not beat. Pour batter into ungreased 9 x 13 inch pan.
 - Bake at 350 degrees F (175 degrees C)for 30 to 35 minutes. Remove cake from oven, but keep it in the pan.
 - Cream together peanut butter, brown sugar, milk, and 1/4 cup butter or margarine. Spread icing onto cake. Place under broiler until brown and bubbly.