Preheat oven to 400 degrees, with rack in center. Lightly coat a standard muffin tin with cooking spray. In a medium bowl, whisk together flour, cornmeal, granulated sugar, baking powder, baking soda, cinnamon, salt, and orange zest, if using.
In a small bowl, whisk together buttermilk, egg yolks, and butter. Stir buttermilk mixture into flour mixture until just blended. In a mixing bowl, whisk the egg whites until just stiff. Gently fold whites and blueberries into the batter until just combined.
Spoon batter into prepared muffin tin, filling each cup three-quarters full. Bake 12 minutes. Remove from oven; gently brush tops with buttermilk, and sprinkle with sanding sugar, if desired. Continue baking until tops are golden and a cake tester inserted in a muffin center comes out clean, 6 to 8 minutes more. Let muffins cool slightly, about 10 minutes, before turning out of tin.
Recipe also appeared in Annual Recipes 2004
Deelish!! Made these from my Martha 2004 cookbook! Actually not sure if I used cornmeal or polenta, but whatever I used they were scrumptious!
These muffins are so moist