Preheat the oven to 350°. Grease a 10" x 5" x 3 ½" loaf pan and set aside. I also like to line the pan with parchment paper, leaving an overhang over the sides. This will ensure the bread removes easily from the pan.
In a large bowl, whisk together the sugar, flour, baking soda, cinnamon, salt and baking powder.
In a separate large bowl, beat the eggs and vanilla and combine with the mashed bananas.
Pour the wet ingredients over the dry ingredients and mix together until just combined. Stir in the melted butter until fully incorporated. Fold in the walnuts or pecans.
Pour the batter into the prepared pan. Prepare the streusel topping by stirring the brown sugar, flour, cinnamon and salt together. Use a fork to mix in the butter until small clumps form. Evenly sprinkle the streusel topping over the batter.
Bake in preheated oven until golden brown and a cake tester inserted in the center of the loaf comes out clean, about 1 hour and 10 minutes. Allow to cool for 20 minutes before slicing.
Notes
If desired, you can toss an extra few tablespoons of chopped pecans or walnuts with the streusel for the top of the bread.If you don’t have a 10x5-inch loaf pan, you can make this bread into muffins instead. Divide the batter between 24 lined muffin tin wells. Bake at 350°F for 20-25 minutes.Recipe adapted from Dominique Ansel’s banana bread.Makes 1 10x5-inch loaf.