1 c. sugar
3/4 c. butter
2 1/2 c. flour
1 c. sour cream
2 eggs
1 tsp. baking powder
1 tsp. baking soda
1 tsp. vanilla
1 (6 oz.) pkg. chips
1/2 c. packed light brown sugar
1 1/2 tsp. cocoa
1/2 c. chopped walnuts

Preheat oven to 350 degrees. Grease 9 inch tube pan.

In large bowl, with mixer at medium speed, beat sugar with 1/2 cup butter until light and fluffy. Add 2 cups flour, sour cream, eggs, baking powder, baking soda and vanilla; beat at low speed until blended, constantly scraping bowl with rubber spatula. Increase speed to medium, beat 3 minutes, occasionally scraping bowl. With spoon, stir in 1/2 cup chocolate pieces. Spread batter evenly in pan.

Into medium bowl, measure 1/2 cup flour, brown sugar and cocoa. With pastry blender or 2 knives used scissor fashion, cut in 1/4 cup butter until mixture resembles coarse crumbs and ingredients are well blended; stir in walnuts and remaining chocolate pieces. Crumble mixture evenly over batter in pan.

Bake 60 to 65 minutes until cake pulls away from sides of pan. Cool cake completely in pan on wire rack. With small spatula, loosen cake from pan; remove to cake plate. Makes 8 to 10 servings.