Preheat oven to 400 degrees F.
Mix dry ingredients (cornmeal, flour, salt, sugar, and baking powder) together with a whisk in a large bowl until well combined.
Pour in milk, egg, and melted butter and whisk until the dry ingredients are fully incorporated with the wet and no lumps are present.
Grease 8x8 glass baking dish or 8-9 inch cast iron skillet with olive oil, covering bottom and sides.
Pour in cornbread batter into baking dish, using a scraper spatula to scrape out the entirety of the batter.
Bake at 400 degrees for 25 minutes or until top is golden brown and a toothpick comes out clean when inserted in the middle.
