Barb's Chocolate Cake

In a large mixing bowl, add the following ingredients one at a time, beating well after each addition: eggs, white sugar, 2 tablespoons butter or margarine, oil, 1/2 cup cocoa, buttermilk and vanilla. (Instead of buttermilk you can use 3 tablespoons softened butter or margarine, 1/2 cup milk and 1 tablespoon vinegar.) Sift the flour, baking powder, baking soda, and salt; add to the sugar and egg mixture. Blend well. Fold in the boiling water. Place batter in two greased and floured 8 inch round cake pans. Sprinkle 1/2 cup chocolate chips over each pan. Bake at 350 degrees F (175 degrees C) for 25 minutes. Cool. To Make the Icing: Begin by beating together 1/2 cup butter or margarine, confectioners' sugar and 2/3 cup cocoa; add 1 teaspoon vanilla, milk and coffee. Beat until very smooth. Add more confectioners' sugar until you obtain the consistency you want. Spread on cake.