Preheat the air fryer. Set it to 325°F (165°C). Preheating helps the muffins rise and brown evenly.

Prep your cups. Lightly spray silicone or metal muffin cups with nonstick spray, or use paper liners in a compatible muffin pan that fits your air fryer. Place them on a small tray for easy transfer if your basket is wobbly.

Mix the wet ingredients. In a large bowl, mash the bananas until mostly smooth. Whisk in the granulated sugar, brown sugar, oil, eggs, and vanilla until combined and glossy.

Combine the dry ingredients. In a separate bowl, whisk the flour, baking powder, baking soda, salt, and cinnamon. This prevents clumps and ensures even leavening.

Bring the batter together. Add the dry ingredients to the wet ingredients. Stir gently with a spatula until just combined. A few streaks of flour are okay.

Fold in mix-ins. If using chocolate chips, nuts, or blueberries, fold them in now. Avoid overmixing to keep the muffins tender.

Fill the cups. Divide the batter among the muffin cups, filling each about 3/4 full. This recipe makes about 10–12 standard muffins depending on cup size.

Air fry in batches. Arrange 4–6 muffins in the basket, leaving space for air to circulate. Cook at 325°F (165°C) for 12–15 minutes. Muffins are done when the tops are set and a toothpick comes out clean or with a few moist crumbs.

Cool briefly. Let muffins rest in the cups for 5 minutes, then transfer to a wire rack to cool completely. Repeat with remaining batter.

Serve. Enjoy warm as-is or with a pat of butter or a drizzle of honey.