Preheat the oven to 350°F. Grease a 9x5-inch loaf pan and set aside.
In a large bowl, whisk together the flour, sugar, baking powder, nutmeg, and salt.
In a separate bowl, beat the eggs, then add milk, sour cream, and melted butter. Mix until well combined.
Pour the wet ingredients into dry ingredients and stir until just combined. Do not overmix.
Pour batter into prepared loaf pan and smooth the top.
Bake for 55 minutes, or until a toothpick inserted into the center comes out mostly clean.
Remove from oven and let cool in the pan for 10 minutes. Then, transfer to a wire rack to cool completely.
In a small bowl, mix together the granulated sugar and ground cinnamon until well combined.
Brush the top of the baked and cooled loaf with melted butter.
Sprinkle the cinnamon sugar mixture generously over the top of the loaf.
Slice and serve the loaf while still warm.
