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 8x14 inch loaf pans. Sprinkle 1 cup coarsely chopped pecans or walnuts evenly over batter in pans.
BAKE at 350° for 1 hour or until a long wooden pick 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 or muffins in pans 10 minutes. Remove from pans to wire racks.
STIR together 2 cups powdered sugar, 6 Tbsp. freshly squeezed orange juice, and 2 tsp. grated orange peel until blended. Drizzle evenly over warm bread or muffins, and cool 30 minutes on wire racks.