Preheat the oven to 375°F. Spray a mini muffin pan with non-stick spray and set aside.
Using mixer, cream together the butter, sugars and vanilla extract until light and fluffy for 2 minutes.
Add in the egg and mix until combined.
In another bowl, whisk together the flour, baking powder, baking soda, salt, nutmeg and cinnamon.
Slowly alternate, back and forth adding the flour mixture & the buttermilk into the bowl of the stand mixer. Mix just until combined. Do not overmix for nice soft, tender, fluffy muffins.
Using a small scoop, scoop up the batter and place into each tin. The small ice cream scoop works wonderful for this and measures out evenly every time. Tins should be filled 3/4 of the way.
Transfer muffins to oven and bake for 8-10 minutes or until done.
Remove them from the oven, and let them cool for a couple of minutes.
While cooling, melt the butter for the cinnamon-sugar topping.
Dip the tops of each muffin in the butter, then roll in the cinnamon sugar mixture.
Serve warm or room temperature.