French Breakfast Muffins

Muffins
2 cups flour
2/3 cup sugar
2 1/2 teaspoons baking powder
1/2 teaspoon salt
1/4 teaspoon nutmeg
1 large egg
1 cup plus 2 tablespoons milk
6 tablespoons unsalted butter, melted and slightly cooled
1 teaspoon vanilla extract
Cinnamon-Sugar Topping
1/2 cup sugar
1/2 teaspoon cinnamon
2 tablespoons unsalted butter, melted and slightly cooled

Preheat the oven to 375°. Butter the bottoms (only) of 12 standard-size muffin cups and set the pan aside.
Measure the flour, sugar, baking powder, salt, and nutmeg into a large mixing bowl and combine them with a whisk.
In a medium-size bowl, whisk the egg until it's frothy. Blend in the milk, melted butter, and vanilla extract. Make a well in the dry ingredients and pour in the liquid mixture.
Using a wooden spoon, mix the batter just until it's evenly blended, then spoon it into the muffin cups, filling each about two-thirds full.
Bake the muffins on the center rack for 15 minutes. Then rotate the pan and bake for an additional 5 to 7 minutes. Transfer the pan to a wire rack until the muffins are cool enough to handle, about 5 minutes, then remove them from the cups.
Before the muffins lose their warmth, prepare the topping. Mix the sugar and the cinnamon in a small bowl. Melt the butter and transfer it to a separate small bowl. Set both bowls next to the muffins.
Working one muffin at a time, quickly dip the tops in the melted butter and then in the cinnamon sugar, rolling each muffin in all directions to cover the entire top. If you'd like more topping, roll them in the cinnamon sugar for a second time while they're still warm. Serve immediately. Makes 12 muffins.