2 c. flour
1 tsp. baking powder
1 tsp. baking soda
3 eggs
1/2 c. soft butter
1 c. sugar
1 tsp. vanilla
1 c. sour cream
1 1/2 c. chocolate bits

TOPPING:

1 tbsp. flour
1/2 c. packed brown sugar
2 tbsp. soft butter
1/2 c. chopped nuts
1/2 c. chocolate bits

In a small bowl, combine flour, baking powder, and soda; set aside. In a large bowl, combine butter, sugar, and vanilla. Beat until creamy. Add eggs, one at a time, beating well after each addition. Gradually add flour mixture alternately with sour cream. Fold in remaining 1 1/2 cups chocolate bits. Spread into a greased 13 x 9 inch baking pan. Sprinkle topping evenly over batter. Bake at 350 degrees for 45 to 50 minutes.