<p>In a bowl, whisk together the flour, cornmeal, sugar, baking powder, baking soda, and salt.</p><p>In a bowl or a large measuring cup, whisk together the milk, melted butter, vegetable oil, and the egg.</p><p>Pour the liquid all at once into the flour mixture, stirring quickly and gently until just combined. Do not overmix: stir the batter just enough to combine and evenly moisten the ingredients.</p><p>Divide the batter into muffin molds and bake in the oven.&nbsp;</p>