1 Preheat oven to 350°F.2 Melt margarine and add cocoa; mix. Stir in sugar and blend in the eggs, one at a time. Add vanilla. Stir in flour and nuts; mix well.3 Bake in greased 9 x 13-inch pan for 30 minutes in preheated oven. Let cool on rack, 20 to 30 minutes. Cut into 20 square pieces.