1/3 cup packed brown sugar
1 tablespoon all-purpose flour
2 tablespoons butter or margarine, softened
1/2 cup chopped nuts
2 cups (12-oz. pkg.) Semi-Sweet Chocolate Mini Morsels, divided
1 3/4 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
1/4 teaspoon salt
3/4 cup granulated sugar
1/2 cup (1 stick) butter or margarine, softened
1 teaspoon vanilla extract
3 large eggs
1 cup sour cream
PREHEAT oven to 350° F. Grease 13 x 9-inch baking pan.
COMBINE brown sugar, flour and butter in small bowl with pastry blender or two knives until mixture is crumbly. Stir in nuts and 1/2 cup morsels.
COMBINE flour, baking powder, baking soda and salt in small bowl. Beat granulated sugar, butter and vanilla extract in large mixer bowl until creamy. Add eggs, one at a time, beating well after each addition. Gradually add flour mixture alternately with sour cream. Fold in remaining morsels. Spread into prepared baking pan; sprinkle with topping.
BAKE 25 to 35 minutes or until wooden pick inserted in center comes out clean. Cool in pan on wire rack.