(2 ¼ cups flour, 1 teaspoons baking soda, 1 teaspoons salt): Combine flour, baking soda, and salt in large mixing bowl.
(½ cup butter (1 stick), ½ cup margarine (1 stick), ¾ cup granulated sugar, ¾ cup packed brown sugar, 1 teaspoons vanilla extract): Beat butter and margarine, granulated sugar, brown sugar, and vanilla extract in large mixing bowl until creamy.
( 2 large eggs, Mixture from step one, 2 cups (12 oz.) chocolate chips, nuts if desired): Add eggs, one at a time, beating well after each addition. Gradually beat in flour mixture. Stir in or beat in chocolate chips. May add nuts if desired.
Spread dough in greased 15x10 inch pan. Smooth so it is even. Place in refrigerator so it becomes firm.
(½ cup butter (1 stick), ½ cup margarine (1 stick), 4 oz. unsweetened baking chocolate, cut up.): Melt butter, margarine, and baking chocolate together in microwave. Stir.
Preheat oven to 350 degrees. You should finish step eight a bit after it is preheated; if you finish early, wait for the oven to preheat before proceeding to step nine.
(2 cups sugar, 4 large eggs, 2 teaspoons vanilla, 1 ½ cups flour): Mix in (in order) sugar, eggs (one at a time), vanilla, and flour. Add nuts if desired.
Remove pan from refrigerator. Pour batter on top of dough. Smooth so it is even. Sprinkle on chocolate chips.
Bake in oven on center rack for 35-40 minutes or until a toothpick comes out relatively clean (it probably will not be completely clean, unlike normal brownies).