Step 1

Preheat oven to 350 degrees F (175 degrees C). Grease a 9x5-inch loaf pan.

Step 2

Stir the bananas and vinegar together in a bowl, and set aside. Cream the sugar and butter together in a large bowl until creamy and smooth, then beat in the eggs. Stir in the reserved banana mixture. In a separate bowl, stir the flour, baking soda, baking powder, and salt together until the mixture is free of lumps. Mix the flour mixture into the butter-sugar mixture until well blended, and stir in the chopped walnuts and chocolate chips. Spread the batter into the prepared loaf pan.

Step 3

Bake in the preheated oven until lightly browned and a toothpick inserted into the center of the loaf comes out clean, 50 to 60 minutes. Let cool in pan about 5 minutes, then turn out onto a wire rack.