Cream together butter and sugar. Add eggs and beat until smooth. Add vanilla and bananas. Mix well till smooth. Sift flour, baking powder and baking soda. Add to banana mixture alternately with sour cream, ending with dry ingredients. Pour half of the batter into 9 x 13-inch pan.
Combine cinnamon and brown sugar. Sprinkle 1/2 of this mixture over batter in pan. Top with 1/2 of the chocolate chips. Repeat layers.