Preheat oven to 350 degrees and greased or line a muffin tin.
Combine flour, baking powder, salt, nutmeg and cinnamon in a bowl. In a separate bowl or large liquid measuring cup, whisk the melted butter, sugar, egg, milk, and vanilla together. Add wet ingredients to dry ingredients and stir to combine.
Spoon batter evenly into muffin tin and bake for 15-20 minutes, until a toothpick inserted in the center of a muffin comes out clean.
While the muffins are baking, melt the butter in a bowl. In a separate bowl, combine the sugar with the cinnamon.
While the muffins are still warm, remove from the pan and dip muffins in butter then into the cinnamon/sugar mixture. Enjoy!
Notes
I subbed half of the flour with whole wheat flour and they were still moist and delicious!Recipe adapted from here.