Preheat oven to 350°F and line a muffin tin with 12 paper liners.
In a large bowl, whisk together the gluten free flour, xanthan gum, corn meal, sugar, baking powder, and sea salt.
In a medium bowl, whisk together the milk, oil, and eggs. Pour the wet ingredients into the dry ingredients and stir until combined.
Transfer the batter to the prepared muffin tin, dividing it equally between the 12 cups.
Bake for 20-25 minutes (see notes for baking time). Cool in the pan for 5 minutes before removing and cooling on a wire rack.
Notes
Baking time will vary depending on the oven and the flour you use. Check for doneness after 20 minutes and then check after another 2 minutes. Muffins are done when a toothpick comes out clean or with moist crumbs.
These muffins freeze well. Defrost at room temperature.