Prep the pan: Heat the oven to 350°F (175°C). Line a mini muffin tin with paper liners or lightly grease with oil or butter.
Mash the banana: In a large bowl, mash the ripe banana until mostly smooth with just a few small lumps.
Whisk in the wet ingredients: Add applesauce, egg, maple syrup or honey, milk, oil, and vanilla. Whisk until well combined.
Mix the dry ingredients: In a separate bowl, stir together flour, baking powder, baking soda, cinnamon, and salt.
Combine gently: Add the dry mix to the wet bowl.
Stir with a spatula just until no dry streaks remain. Do not overmix. Fold in any optional add-ins.
Fill the cups: Divide the batter among the mini muffin cups, filling each about 3/4 full.
Bake: Bake for 10–13 minutes, or until the tops spring back when lightly pressed and a toothpick comes out clean or with a few moist crumbs.
Cool: Let the cupcakes rest in the pan for 5 minutes, then transfer to a wire rack to cool completely.
They’ll firm up as they cool but stay soft.
Serve: Enjoy plain, or top with a thin smear of yogurt for older toddlers right before serving.