1 c. flour
1 c. sugar
1 tsp. baking powder
1 tsp. vanilla
1/2 tsp. salt
1/2 c. soft butter
1 c. chopped walnuts
2 eggs
1 square chocolate

Combine all ingredients except chocolate in mixing bowl. Beat at medium speed for 2 minutes. Spoon half of batter here and there in buttered and floured 9"x13" pan. Stir melted chocolate into remaining batter and spoon between light batter, spread and swirl batter. Bake 20 to 25 minutes at 350 degrees. It is best to add walnuts after batter is mixed.