Prep: 1. Preheat oven to 375. 2. If you’re using buttermilk or yogurt, ignore this step. If not, make soured milk: Warm the milk gently—about 1 minute in the microwave is enough—and add the vinegar. Let it rest while you prepare the other ingredients. Make: 1. Butter an 8x8 baking dish (or 8 inch oven proof skillet if you have one). 2. In a bowl mix cornmeal, flour, baking powder, salt and sugar. 3. Mix the egg into the buttermilk. 4. Add wet ingredients to dry ingredients, stirring just enough to combine; if it seems too dry, add another splash of buttermilk. 5. Pour batter into prepared skillet or pan and smooth out the top if necessary. 6. Bake about 30 minutes, until the top is lightly browned and a toothpick inserted into the center comes out clean. Serve hot or warm.
*You can use buttermilk, milk, or yogurt (or 1 1/4 cups milk plus 1 tablespoon white vinegar; see Step 2)