Cranberry Upsidedown Cake

The girl that I can my "eater" is home for a week. This inspires me to make food. No only does she appreciate my cooking, she is happy to eat leftovers. She also reveals that the college food is lacking in fruits and veggies, so her body craves to be renourished.
Last night I had a bit of a cooking frenzy. Porktenderloin, rice with raisins and walnuts, eggplant curry and Cranberry Upside down cake. I have been trying some cakes lately as my hubby's 50th is coming up. Usually I just make a flourless chocolate cake or some such thing, but I want to make a "real" cake for the big day. I just substituted gluten free flour mix for the all-purpose and, tada, a real cake. I'm going to try this again with pineapple as that is one of his favorites.
This cake is easy and comes out very moist and yummy. The leavening is done by the egg whites and baking powder. I had no milk in the house, so I used instant dry milk and water.
This is adapted from a Cooking Light recipe published in November or 2009.

Cranberry Upside-Down Cake

For the topping
1/3 cup packed brown sugar
2 TBSP trans fat free mararine
6 ounces fresh or frozen-thawed cranberries

For the Cake
1 1/2 cups gluten free flour mix (or all-purpose flour)
2 tsp baking powder
1 cup gransulated sugar
1/2 cup tranfat free margarine- softened
2 large egg yolds
1 tsp vanilla
1/2 cup skim milk
2 large egg whites

1. preheat oven to 350 degrees. Prepare 9-inch round cake pan with cooking spray. Melt brown sugar and 2 tbsp margarine in small microwavable bowl. Pour into prepared cake pan, tilting to coat. Arrange cranberries evenly over sugar mixture. Add more if needed.
2. Combine flour, baking pwder andsalt in small bowl. In a large bowl cream together margarine and sugar. Add egg yolks one at at time. Beat in vanilla. Fold flour mixture into sugar mixture alternately with milk.
3. Beat the egg whites with a misuter at high speed until stiff peaks form. Be sure the beaters are clean and there is no yolk in with the whites. Gently fold the egg whites into the batter. Spoon the batter over the cranberries, spread evenly. The batter should be a bit thick.
4. Bake at 350 degrees for 55 minutes or until wooden pick comes out clean. Cool in pan for 15 minutes on a wire rack. Loosen cake from sides with a spatula and turn onto a plate.
Serve warm or at room temp.