Cranberry Upside Down Muffins

From your kitchen:
2 cups all-purpose flour
1/2 cup granulated white sugar
2 1/4 teaspoons baking powder
1/2 teaspoon salt
1 cup milk
1 large egg, lightly beaten
1 teaspoon pure vanilla extract
4 tablespoons unsalted butter, melted and cooled
1 cup prepared cranberry sauce

Preheat oven to 400 degrees F. Place rack in the middle of the oven. Spray, with a non stick vegetable spray, 12 muffin tins. In a large mixing bowl, combine the flour, sugar, baking powder, and salt. In a separate bowl, mix together the milk, egg, vanilla extract, and melted and cooled butter. Add the milk and egg mixture to the flour mixture. Stir just until combined. Do not over mix the batter or the muffins will be tough when baked. Evenly divide the cranberry mixture among the 12 well greased muffins cups and then evenly spoon the batter over the cranberry sauce. Place in the oven and bake for about 15 to 20 minutes, or until very lightly browned and a toothpick inserted in the center comes out clean. Place on a wire rack to cool for about 2 minutes, and then invert them onto a cooling rack so the the cranberry topping is face up.