In a large bowl, mix together banana, mayonnaise, egg, and vanilla.
In a medium bowl, whisk together flour, sugar, nuts, baking soda, and salt.
Add flour mixture to banana mixture and stir until just combined.
Bake 60-70 minutes, or until a toothpick comes out clean. Cool for 15 minutes in the pan then place on a cooling rack. Cool completely. Slice and serve!
Notes
Do not overmix the batter for a more light and airy loaf.
Scoop flour into the measuring cup instead of scooping directly from the bag.
Toss add-ins with flour to keep them from sinking to the bottom of the loaf while it bakes.
Check for doneness using a wooden pick inserted into the center of the loaf about 10 minutes before the end of the cooking time. Check again at 5 minute intervals after that.
Store banana bread at room temperature wrapped in plastic wrap or foil for up to 5 days.
Freeze loaf whole, or wrap individually and place in a zippered bag for up to 2 months.