In a large bowl, combine sugar, flour, and salt; set aside. In a saucepan, bring margarine, water, and cocoa, to a boil. Take from heat and immediatley pour over dry ingredients, stirring to mix. Then add sour cream, eggs, and soda. Mix well (until uniform in color). Pour into greased and floured 11 1/2 X 15 1/2 -inch pan. Bake at 375 degrees for 25-30 minutes, frost cake while warm. Have ingredients ready, but do not make frosting until cake comes out of the oven.

Leave brownies with just chocolate frosting or add some holiday designs of your own to each cut piece.

Frosting:.

6 tablespoons milk.

1/2 cup margarine.

4 tablespoons cocoa.

1 cup chopped nuts (optional).

1 teaspoon vanilla.

1 box powdered sugar.

Boil milk, margarine, and cocoa until bubbly. Remove from heat and add nuts, vanilla, and sugar. Mix until smooth; spread on warm cake. Let frosting set. Pipe on holiday design of your making if you like.