Preheat your oven to 375 degrees f. and lightly spray a 12-cup regular muffin tin with cooking oil spray.
In a large bowl, mash the banana. Add in the oats, milk, 1/4 cup of peanut butter, eggs, honey baking powder and vanilla. Stir well to combine, then add about 2 spoonfuls of batter to each of your prepared muffin cups.
Divide the remaining 1/4 cup of peanut butter, by adding a teaspoon to each muffin. Sprinkle in half of your chocolate chips.
Cover the peanut butter with the remaining batter and top with the remaining chocolate chips.
Bake for about 25 minutes, or until a toothpick inserted in the center comes out clean.
Allow the muffins to cool before serving.
Enjoy!