Preheat the oven to 350°F. Spray an 8 ½ x 4 ½-inch loaf pan with nonstick cooking spray.
In a large bowl, whisk together the flour, sugar, baking powder, salt, and nutmeg.
In a separate bowl, whisk together the milk, egg, melted butter, and vanilla.
Pour the wet ingredients into the dry ingredients and stir gently until just combined. Do not overmix.
Pour the batter into the prepared loaf pan and spread evenly.
Bake for 60 to 70 minutes, or until a toothpick inserted into the center comes out with a few crumbs and the top is golden.
Let the bread cool in the pan for 10 minutes, then remove and place on parchment paper.
While still warm, brush the entire loaf with melted butter.
In a small bowl, mix the sugar, cinnamon, and nutmeg. Sprinkle evenly over the loaf, turning as needed to coat all sides.