Preheat your oven to 350°F (175°C) and get your muffin tin ready by lining it with liners or giving it a light grease, whatever makes things easiest for you.
Take your ripe bananas, strip off the skins, and mash them well in a big bowl. Leaving a few small lumps is perfect, they add natural sweetness and a little bit of texture that makes these muffins feel homemade.
Stir in the milk, honey, and vanilla until the mixture is smooth and creamy. At this point, your kitchen will start smelling amazing, and that’s a sign you’re on the right track.
Add the oats, cinnamon, nutmeg, baking powder, and salt. Fold everything together gently until combined, don’t overmix, or the muffins might turn out dense instead of soft and tender.
Mix in most of the mini chocolate chips, saving a few to sprinkle on top. This gives every muffin little pockets of melty chocolate and a fun, chocolatey finish.
Portion the batter into the muffin cups, filling each one roughly three-quarters of the way up. Top with the reserved chocolate chips, pressing them lightly if you want them to peek through for a pretty, bakery-style look.
Bake for around 26 minutes, or until the tops are lightly golden and a toothpick comes out clean from the center. Let the muffins cool slightly before enjoying, or dig in warm if you can’t resist!