Preheat a large cast iron or nonstick skillet over medium heat, or heat a griddle according to the manufacturer’s directions to 350°F.
In a small mixing bowl, whisk together the cornmeal, cornstarch, xanthan gum, granulated sugar, baking powder, baking soda, and salt.
In a blender, place the milk, melted butter, and eggs. Add the dry ingredients on top.
Close the blender canister and give it a quick shake to begin to mix the ingredients so there is liquid and dry ingredients next to the blades.
Blend on high speed until smooth, about 1 minute.
The batter should be thickly pourable. If you omitted the xanthan gum, it will be relatively thin. Allow the batter to sit for 5 minutes to thicken, and whisk until smooth.
Grease the hot skillet or pan with a light brushing of unsalted butter.
Pour or ladle the pancake batter on the hot skillet surface in 1/4-cup portions, taking care not to crowd the skillet or pan.
Allow the pancakes to cook until lots of bubbles appear and the surface appears dry around the edges (about 3 minutes).
Flip the pancakes and continue cooking for another minute, or until the underside is lightly browned. Flip the pancakes again to make sure the underside is cooked and the pancakes are cooked all the way through.
Transfer the cooked pancakes to a baking sheet or serving plate (in a stack to keep them warm), and repeat with the remaining batter.
If you’d like, while you finish the batch, you can keep the cooked pancakes warm in a 200°F oven on a parchment lined baking sheet.
Serve immediately with your favorite pancake toppings.