Preheat the oven to 325 degrees F (165 degrees C). Grease a 10 inch springform pan with cooking spray, and dust with rice flour.
In a large bowl, whip egg yolks with 2/3 cup of sugar until thick and pale using an electric mixer. This will take about 5 minutes. Stir in the rice flour and orange juice, then fold in the almond meal and cinnamon.
In a separate glass or metal bowl, whip 3 egg whites until they can hold a stiff peak. Fold into the almond mixture until well blended. Pour into the prepared pan, and spread evenly.
Bake for 35 to 40 minutes in the preheated oven, until a toothpick inserted into the center comes out clean. Cool in the pan on a wire rack. Run a knife around the outer edge of the cake to help remove it from the pan.
To make the orange sauce, cream together the butter and 2 cups of white sugar in a medium bowl. Stir in the cream, and place the dish over a pan of barely simmering water. Stir in orange juice and zest. Whip 4 egg whites in a separate bowl until soft peaks form. Fold into the orange sauce. Spoon over the cake and serve immediately.
