Preheat and prep. Heat your oven to 350°F (175°C). Line a mini muffin pan with liners or lightly coat with nonstick spray. You can also make small standard-size muffins; just avoid overfilling.

Mash bananas. In a large bowl, mash the ripe bananas until mostly smooth with a few small lumps. Measure to ensure you have about 1 cup.

Whisk the wet ingredients. Add the egg, applesauce, sugar, vanilla, and oil to the bananas. Whisk until well combined and glossy.

Combine the dry ingredients. In a separate small bowl, whisk the flour, baking soda, baking powder, salt, and cinnamon. This helps distribute the leavening evenly.

Fold together. Add the dry mixture to the wet mixture. Use a spatula to fold gently just until no dry streaks remain. Do not overmix, or the muffins can turn tough.

Add nuts. Fold in the chopped walnuts or pecans. If using toasted nuts, make sure they’ve cooled before adding.

Portion. Spoon the batter into the muffin cups. For minis, fill each cup almost to the top. For small standard muffins, aim for about half to two-thirds full.

Bake. Bake mini muffins for 10–13 minutes and small standard muffins for 14–17 minutes. They’re done when the tops spring back lightly and a toothpick comes out with a few moist crumbs.

Cool. Let them rest in the pan for 5 minutes, then move to a wire rack to cool completely. This helps them set and stay tender.

Taste and adjust. Try one warm. If you prefer a bit more sweetness next time, add a teaspoon or two of sugar or a few chocolate chips to the batch.