1Cream together 1 cup of the butter or margarine and the egg. Add 1 cup white sugar, vanilla and hot water. Stir in the flour, cocoa, and baking soda and mix well.
2Drop from a teaspoon onto cookie sheets and bake at 375 degrees F (190 degrees C) for 10 to 12 minutes. Sandwich cookies together with Peanut Butter Frosting.
3To Make Peanut Butter Frosting: Blend 1 tablespoon butter and peanut butter. Stir in confectioners' sugar and add enough milk to make frosting soft enough to spread. Spread between the flat sides of two cookies and sandwich together.