Prepare muffin tin by either greasing lightly with a nonstick spray or lining with paper cupcake liners.
Mash bananas with a fork or potato masher and measure out ¾ cup. Set aside.
¾ cup mashed bananas
Combine flour, baking powder, sugar, cinnamon, and salt together in a bowl.
1½ cups flour, ¾ cup sugar, 2 teaspoons baking powder, 2 teaspoons ground cinnamon, ½ teaspoon salt
In a separate bowl, combine eggs, oil, and vanilla
2 eggs, ½ cup oil, 1 teaspoon vanilla
Add the combined liquids to the flour mixture. Stir just until mixed together. The batter will be very dry.
Add the mashed bananas and fold them together with a spatula until everything is combined.
Scoop batter into a muffin tin that has been lightly greased or lined with paper liners.
Combine remaining cinnamon and sugar together and sprinkle about ½ teaspoon over each muffin.
2 tablespoons sugar, 1 teaspoon cinnamon
Bake in a preheated 375°F oven for 15-18 minutes or until cooked through.
Rest on a baking rack for a few minutes and then remove muffins from tin. Continue cooling muffins on the baking rack.
Notes
Use very ripe bananas. They have the sweetest flavor and the most moisture.
When you first add the wet ingredients to the dry, the mixture will still be very dry. Just stir until slightly combined. Then add the mashed bananas and fold everything together.
Don't overmix or the muffins will become tough.
Use an ice cream scoop for consistently sized muffins.
Test for doneness by inserting a toothpick into the center of one muffin. If the toothpick comes out with moist batter, they need more time. If there are just a few crumbs on the toothpick, they are done!
Store fully cooled muffins at room temperature in an airtight container.