Preheat oven to 375 degrees F (190 degrees C). Prepare two 8 1/2 x 4 1/2 inch loaf pans. Spray with vegetable spray. Cut a piece of parchment paper to fit the bottom of the loaf pan and lay it in.
In a large mixing bowl, combine Egg (4) and Granulated Sugar (1 1/2 cup). Blend on medium speed for about 5 minutes until thick and light-colored.
Add Banana (2 cup), Buttermilk (2/3 cup), and Vanilla Extract (2 tablespoon) and blend until combined.
In a small bowl, combine All-Purpose Flour (2 1/2 cup), Baking Powder (1 1/3 tablespoon), Baking Soda (1 teaspoon), and Salt (1 teaspoon). Stir to distribute ingredients.
Add flour to wet ingredients in 3 additions, being careful not to overmix the batter.
In the same bowl the flour was in, add Mini Chocolate Chips (1 cup). Dust with All-Purpose Flour (1 teaspoon) and mix with your fingers. Stir chips and Walnut (1 cup) into batter.
Spoon batter evenly into the loaf pans. Divide the Semi-Sweet Mini Chocolate Chips (1/4 cup) and Walnut (1/4 cup) over the top of the three loaves.
Bake 35-40 minutes until golden brown.
Cool on a rack for 20 minutes, then turn out the bread and remove the parchment paper. Slice and serve. Enjoy!