Cranberry Ginger Cake

I found this recipe originally and decided to modify it. A lot. It wasn't upside down, it was dairy free. I was a bit worried about the texture before folding in the egg whites but it turned out fabulous.

Cranberry-Ginger Cake

Cooking spray
1 1/2 cups all-purpose flour
2 teaspoons baking powder
1/4 teaspoon salt
1/4 cup butter, softened
1 cup granulated sugar
2 large egg yolks
1/2 cup fat-free milk
1 teaspoon vanilla extract
2 large egg whites
1/4 teaspoon cream of tartar
3/4 cup packed light brown sugar
2 tablespoons butter
1 1/2 tablespoons grated peeled fresh ginger
3 cups fresh cranberries, finely chopped
fat-free whipped topping

Preheat oven to 350°. Coat 9" cake pan with cooking spray.

Heat a skillet over medium heat; coat pan with cooking spray. Add brown sugar and 2 tablespoons butter to pan, stirring until melted. Stir in ginger; cook 1 minute, stirring constantly. Add in chopped cranberries, stirring to coat. Remove from heat and allow to cool.

Lightly spoon flour into dry measuring cups; level with a knife. Combine flour, baking powder, and salt. Combine 1/4 cup butter and granulated sugar in a large bowl; beat with a mixer at high speed until fluffy. Add egg yolks, 1 at a time, beating well after each addition. Add flour mixture and milk alternately to butter mixture, beginning and ending with flour mixture; mix after each addition. Beat in vanilla.

Beat egg whites and cream of tartar with a mixer at medium speed until stiff peaks form. Fold egg whites into batter. Fold cranberries into batter; pour into a prepared cake pan. Bake at 350° for 55 minutes or until a wooden pick inserted in center comes out clean. Cool in pan 15 minutes. Top each serving with whipped topping.