Preheat oven to 375˚F. Grease muffin tin or use cupcake liners.
Whisk flour, brown sugar, baking powder, and salt together in a large bowl.
In a medium bowl, blend bananas, milk, peanut butter, eggs, and butter until well combined.
Add banana mixture to the dry ingredients and fold until just combined, about 20-25 times. Fold in chocolate chips.
Using a 3 Tablespoon cookie scoop, fill muffin tin cups about ¾ full. Bake for 20-25 minutes, or until lightly browned and a toothpick comes out clean.
Allow muffins to cool in the tin for 5 minutes before removing, then place on a cooling rack to finish cooling. Muffins made in paper liners can be removed from tins immediately and placed on cooling rack.
Notes
Yield: 18 muffins, or 12 muffins and 12 mini muffins, or can be made in a loaf pan.
Bake mini muffins for approximately 15 minutes.
Bake in a loaf pan for about 45 minutes.
Use pan release to grease the muffin tin for excellent results!
Substitute 6 Tablespoons mayonnaise in place of eggs if desired.
Store muffins at room temperature in a covered covered container or zippered bag for up to 4 days.
Freeze muffins wrapped in plastic and in a zippered bag, or sealed container, for up to 8 weeks.