Preheat the oven to 375 degrees F. Rub a Madeleine pan generously with butter or shortening.In a medium size mixing bowl, whisk together the cornmeal, flour, sugar, salt, baking powder, and baking soda. Make a hole in the center of the dry mixture and add the buttermilk, and egg.
Whisk those two things together in their little hole, then pour in the butter and mix everything together until you have a uniform batter.Spoon about a heaping tablespoon of batter into each mold. They should be about 2/3 full.
Bake until the center is firm and a cake tester or toothpick inserted into the center comes out clean, 10-12 minutes.
Let cool slightly then pop the Madeleines from the pan. Makes 18 or 19, but that will probably vary depending on the size of your Madeleine molds and how you divide the batter.
