Banana-Chocolate Tea Bread

1/2 cup butter, softened
1 cup sugar
2 eggs
1-1/2 cup all-purpose flour
2 Tb cocoa
1 tp baking soda
1 tp salt
1/2 tp ground cinnamon
1 tp vanilla extract
1 cup mashed banana (about 2-3 bananas)
1/2 cup sour cream
1/2 cup chopped walnuts
1/3 cup mini semi-sweet chocolate chips

Cream butter; gradually add sugar, beating well until light and fluffy. Add eggs, one at a time, beating well after each addition. Combine flour, cocoa, soda, salt and cinnamon; sift together (or mix with a whisk). Stir flour mixture into egg mixture, blending well; add vanilla. Stir in banana, sour cream, walnuts and chocolate chips.
Spoon batter into a greased & floured loaf pan. Bake at 350 degrees for 55 minutes or until toothpick comes out clean. Cool in pan 10 minutes, then remove from pan to finish cooling. (Will make four mini-loaves)