1 c. soft type butter
2 c. sugar
2 tsp. vanilla
6 eggs
1 c. instant flour
1 tsp. baking powder
1/2 tsp. salt
1 c. chopped walnut nuts, divided
4 env. no-melt unsweetened chocolate

Combine all ingredients except 1/2 cup nuts and chocolate in a large bowl of mixer. Blend at low speed 1 minute. Add chocolate. Pour batter into 9"x13" greased pan. Sprinkle with remaining nuts. Bake at 350 degrees for 30 minutes.