1) Combine the gluten-free flour and cornmeal in a large mixing bowl.
2) Pour the buttermilk or cream into the bowl, and stir to evenly moisten the flours. Cover and let sit for 2 to 3 hours, or in the refrigerator overnight.
3) When you're ready to bake, preheat the oven to 375°F. Grease the wells of a 12-cup muffin tin, or line with papers and grease the insides of the papers.
4) Add the butter, honey, egg, baking powder, baking soda, and salt to the moistened flours and beat at high speed for 1 to 2 minutes. This isn't like a wheat-flour muffin, where you have to worry about them getting tough: the beating helps to develop the structure of these muffins.
5) Scoop the batter into the wells of the prepared pan, and bake the muffins for 22 to 24 minutes, until they appear set; a toothpick inserted into the center of one of the muffins in the middle of the pan should come out clean.
6) Remove the muffins from the oven and put the pan on a rack; transfer the muffins from the pan to a cooling rack after 5 minutes, so they don't steam. Serve warm.
Yield: 12 muffins.