Beat butter and cream cheese at medium speed with an electric mixer until creamy. Gradually add sugar, beating until light and fluffy. Add eggs, 1 at a time, beating just until blended after each addition.
Combine flour and next 3 ingredients; gradually add to butter mixture, beating at low speed just until blended. Stir in bananas, pecans, and vanilla. Spoon batter into 2 greased and floured 8x4 inch loafpans.
Bake at 350 degrees for 1 hour or until a long wooden toothpick inserted in center comes out clean and sides pull away from pan, shielding with aluminum foil last 15 minutes to prevent browning, if necessary. Cool bread in pans or wire racks 10 minutes. Remove from pans, and cool 30 minutes on wire racks before slicing.
** Warm bread is yummy, but to get perfect slices, let bread cool 30 minutes, then cut with a serrated or electric knife. **.