Preheat oven to 350 degrees.
In a mixing bowl, whisk together the dry ingredients.
Add banana, egg, sour cream, vanilla, and honey. Barely stir together, then add melted butter and quickly stir together until combined. Stir in grated nutmeg. (Nutmeg is optional, but I love it!)
I'm using tulip muffin liners for this recipe. They can hold a little more batter than a standard muffin cup. If you're using the tulip liners, this recipe will make 6 bakery sized muffins. If you use standard muffin liners, fill them 2/3 full, and you will get a few extra muffins.
Bake at 350 degrees for around 24 minutes, but keep check on the browning. All ovens are different. They're done when they spring back in the middle when touched, or when a toothpick comes put clean. Remove from muffin tin, allow to cool, and enjoy!