Preheat the oven to 400°F (200°C)
Grease an 8-inch square baking pan or cast-iron skillet
In a bowl, mix 1 cup cornmeal, 1 cup all-purpose flour, 1/4 cup sugar, 1 tablespoon baking powder, and 1/2 teaspoon salt
In another bowl, whisk 1 cup milk, 1/4 cup melted butter, and 1 egg
Pour the wet ingredients into the dry ingredients
Stir until just combined
Pour the batter into the prepared pan
Bake for 20 to 25 minutes
Check for a golden top and a toothpick that comes out clean
Let cool slightly before serving