Heat oven to 425 degrees. Grease 12 muffin cups with gluten free cooking spray or gluten free alternative. (may use paper liners, but I prefer not to, so that muffin gets nicely browned on the bottom and sides) In a bowl, combine dry ingredients. Remove 1 tablespoon of dry ingredients, and toss with cranberries; set aside. In another bowl, combine the milk, melted butter and eggs Stir wet ingredients into the the dry. Do not over mix, but stir only until all ingredients are moistened. Add cranberries. Immediately spoon batter into muffin cups. Optional: Sprinkle muffin tops with cinnamon sugar. Bake at 425 for approximately 20 minutes or until tops are lightly browned and a wooden skewer/toothpick comes out clean.