Preheat the oven to 350°F and line a standard muffin pan with paper liners.
In a large bowl lightly beat the eggs. Add the sour cream, melted butter, bananas, and vanilla, and whisk until combined.
Add the flour, baking powder, cinnamon, baking soda, and salt. Stir until just combined.
Divide the batter evenly between the 12 prepared muffin cups.
Bake for 18-20 mins. Cool slightly before serving.
Notes
Your muffin cups will be SUPER full and you will think I gave you bad instructions. Just trust me that filling them up will give you fluffy tall muffin tops -- like the perfect little dome. If you are still uncertain you can actually stretch this batter to yield 13-14 muffins, they just won’t be as tall.