Prep the pan: Preheat oven to 350°F (175°C). Grease a mini muffin tin or line with mini paper liners. This recipe makes about 30–36 mini muffins or 12 standard muffins.
Blend the wet ingredients: In a blender, add bananas, spinach, eggs, milk, melted oil, vanilla, and maple syrup or honey (if using).
Blend until completely smooth and green, about 30–45 seconds.
Combine dry ingredients: In a large bowl, whisk oats, flour, baking powder, baking soda, cinnamon, and salt until well mixed.
Make the batter: Pour the green mixture into the dry ingredients. Stir gently with a spatula until just combined. Avoid overmixing—some small lumps are fine.
Add mix-ins (optional): Fold in 1/4–1/3 cup mini chocolate chips, blueberries, or seeds if you’d like.
Keep mix-ins small for toddler safety.
Fill the tins: Spoon batter into the prepared muffin cups, filling each about 3/4 full. The batter is thick—use two spoons for easier scooping.
Bake: For mini muffins, bake 12–15 minutes. For standard muffins, bake 18–22 minutes.
They’re done when a toothpick comes out clean or with a few moist crumbs.
Cool completely: Let muffins rest in the pan for 5 minutes, then transfer to a wire rack. Cooling helps them set and prevents crumbling.
Serve: Offer whole for older toddlers or cut into halves/quarters for beginners. Spread with a thin layer of yogurt or nut/seed butter if desired.