Preheat the oven to 425°F.
In a large bowl, whisk together cornmeal, flour, sugar, baking powder, and salt.
In a separate bowl, whisk together milk, melted butter, and egg.
When the oven is preheated, add the oil to a 9-inch round cake pan or cast-iron skillet and place the pan in the oven to heat for 5 minutes.
Once the pan has been in the oven for 5 minutes, make a well in the center of the flour mixture.
Pour the milk mixture into the flour mixture, and whisk together just until combined.
Remove the hot pan from the oven and immediately pour in the batter. (The batter should sizzle!)
Bake for 18 to 22 minutes or until a wooden pick inserted in the center comes out clean.
For a crisp crust, remove it from the pan immediately by inverting the cornbread onto a wire rack.
Let it cool for 5 to 10 minutes before serving.
