Preheat oven to 350 °F. Lightly oil a 9×5-inch loaf pan.
Stir together mashed bananas and buttermilk; set aside.
Cream brown sugar and margarine together until fluffy. Beat in egg. Add banana mixture; beat well.
Sift together flour, baking powder, baking soda, and salt; add all at once to liquid ingredients. Stir until well blended.
Stir in nuts, and turn into the prepared pan.
Bake for 50 to 55 minutes, or until a toothpick inserted in the center comes out clean. Cool for 5 minutes in the pan.
7
Remove from pan and complete cooling on a wire rack before slicing.
Bake for 50 to 55 minutes, or until a toothpick inserted in the center comes out clean. Cool for 5 minutes in the pan.
Remove from pan and complete cooling on a wire rack before slicing.