2 1/4 c. all-purpose flour
2 c. brown sugar, firmly packed
1 c. peanut butter
1/2 c. butter, softened
1 tsp. baking powder
1/2 tsp. baking soda
1 c. milk
1 tsp. vanilla
3 eggs
1 (10 oz.) pkg. semi-sweet chocolate pieces (reserve 1/2 cup for glaze)

GLAZE:

Reserved chocolate pieces
1 tbsp. butter
2 tbsp. milk
1/2 c. powdered sugar

Preheat oven to 350 degrees (325 degrees for colored fluted tube pan). Using solid shortening or butter (not oil), grease and flour 12-cup fluted tube pan (non-stick finish pan, too). (Lightly spoon flour into measuring cup; level off.) In large bowl, blend first 4 ingredients at low speed until crumbly; reserve 1 cup. Add remaining ingredients, except Glaze to crumb mixture in mixing bowl. Blend at low speed until moistened; beat 3 minutes at medium speed. Pour 2 1/2 cups batter into prepared pan. Sprinkle with reserved crumb mixture and 1/2 cup chocolate pieces; spread remaining batter over crumb mixture. Bake 55 to 65 minutes or until toothpick inserted in center comes out clean. Cool upright in pan 45 minutes; turn onto serving plate. Cool completely. In small saucepan over low heat, blend first 3 Glaze ingredients, stirring constantly until chocolate pieces melt. Remove from heat. Stir in powdered sugar until smooth. Add additional milk if necessary for glazing consistency.