Adjust the oven rack to the middle position. Preheat oven to 350°F. Grease and flour a 9-inch round cake pan. Line the bottom with a 9-inch parchment paper round and then spray with nonstick cooking spray. Set aside.
In a medium-sized saucepan, melt the butter for the topping. Add remaining topping ingredients. Cook over a medium heat until cranberries begin to soften, approximately 3 minutes. Strain cranberries from the juice. Put cranberries into the bottom of the prepared cake pan in a single layer. Return 1/2 cup of juice to the saucepan. Discard the rest. (I only had 1/2 cup of juice so used all of it. Continue cooking until thickened, approximately 5 minutes. Once thickened spread the sauce over the cranberries. Refrigerate while you prepare the cake.
In a medium-sized bowl, sift flour, baking powder and salt together. Set aside.
In the bowl of an electric stand mixer, cream butter and sugar together until fluffy. Add vanilla and then egg yolks one at a time. Mix until well combined.
Alternate adding flour mixture and heavy cream, beating on low speed just until combined.
In a small mixing bowl add egg whites and cream of tarter. Beat until stiff peaks form. Fold egg whites gently into cake batter.
Gently spoon batter over cranberries, smoothing the top out evenly.
Bake 40 to 50 minutes until top is browned and center springs back. Cool on a wire rack for 10 minutes. Run a paring knife around the edge of the pan and invert the cake onto a serving plate. Remove the parchment paper carefully. Allow to cool completely before serving.