In a large bowl, cream together butter and sugar. Add eggs, one at a time, beating after each addition. Sift dry ingredients together; add to creamed mixture. Stir in bananas and chopped pecans. Pour batter into 2 well-greased loaf pans; bake at 325° for about 1 hour and 15 minutes, or until a toothpick inserted in center comes out clean. Makes 2 loaves.