Step 1

Preheat oven to 325 degrees F. Grease and flour a 9x5 inch loaf pan. Set aside.

Step 2

The streusel topping. Add the flour, brown sugar, and cinnamon in a medium bowl and mix until combined. Cut in the butter using your fingers or a pastry blender, until it resembles coarse crumbs. Stir in chopped walnuts. Set aside.

Step 3

In a medium bowl, whisk together flour, baking powder, baking soda, salt, cinnamon and nutmeg. Set aside.

Step 4

Cream the butter and sugars in a large mixing bowl until light and fluffy. Add the eggs, one at a time, beating well in between each addition. With a wooden spoon, stir in the mashed bananas, buttermilk and vanilla. Slowly stir in the dry ingredients. Once the flour is incorporated, stop right there. Do NOT over stir. Gently stir in walnuts. The batter will be thick.

Step 5

Pour the batter into the prepared loaf pan. Sprinkle the streusel topping evenly over the batter. Bake the bread for 1 hour to 1 hour 10 minutes, or until a toothpick inserted into the center of the loaf comes out clean.

Step 6

Remove from oven and cool 10-15 minutes in the pan on a wire rack. Remove the bread from the pan and continue to cool on the wire rack. Serve warm or at room temperature.