Heat oven to 350ºF.
Beat butter and sugar in large bowl with mixer until blended.
Add eggs and sour cream; mix well.
Add bananas and combined dry ingredients; mix just until moistened. Stir in chocolate chips.
Pour into greased and floured 9×5-inch loaf pan.Bake 1 hour or until toothpick inserted in center comes out clean.
Cool for 5 min.; remove from pan to wire rack.
Cool completely before slicing. Refrigerate leftovers.