1. Preheat oven to 350°. Place pecans in a single layer on a baking sheet, and bake 12 to 15 minutes or until toasted and fragrant, stirring after 6 minutes. Remove and reserve 1/4 cup toasted pecans.
2. Beat softened butter and cream cheese at medium speed with an electric mixer until creamy. Gradually add 1 cup granulated sugar, beating until light and fluffy. Add eggs, 1 at a time, beating just until blended after each addition.
3. Combine whole wheat flour and next 4 ingredients; gradually add to butter mixture alternately with buttermilk, beginning and ending with flour mixture. Beat at low speed just until blended after each addition. Stir in bananas, 3/4 cup toasted pecans, and 1/2 teaspoon vanilla. Spoon batter into 2 greased and floured 8- x 4-inch loaf pans.
4. Bake at 350° for 1 hour or until a long wooden pick inserted in center comes out clean and sides of bread pull away from pan, shielding with aluminum foil during last 15 minutes to prevent excessive browning, if necessary.
5. Meanwhile, cook evaporated milk, 2 Tbsp. granulated sugar, 2 Tbsp. brown sugar, and 1 Tbsp. butter in a small saucepan over medium heat, stirring constantly, 3 to 4 minutes or until bubbly. Remove from heat. Stir in coconut, reserved toasted pecans, and 1/2 tsp. vanilla extract.
6. Remove bread from oven; immediately spread tops lightly with coconut mixture. Broil 5 1/2 inches from heat 2 to 3 minutes or until topping starts to lightly brown. Cool in pans on wire racks 20 minutes. Remove from pans to wire racks; cool 30 minutes before slicing.