Preheat the oven to 350 degrees.
In a large bowl, combine the melted butter, brown sugar, and white sugar. Add the eggs and vanilla and mix until the mixture is smooth.
Add the all-purpose flour, baking soda, baking powder, and salt to the bowl. Mix until well combined; the batter will be thick, but don't worry.
Gently fold in the ripe bananas, sour cream (Greek yogurt), melted peanut butter, and chocolate chips.
Line 2 muffin tins with muffin liners, making a total of 24 muffins. Spoon about 2 tablespoons of batter into each muffin cup.
Bake in the preheated oven for 18-20 minutes, or until the tops of the muffins are golden brown and the centers are cooked through.
Allow the muffins to cool for about 5 minutes before removing them from the muffin tins.