Flourless Chocolate Cake

1 butter flavored cooking spray
5 egg whites
4 oz Baking Chocolate, bar, semi sweet , chopped
3 tbsp unsweetened cocoa powder
1/2 cup ground walnuts , ground (or almonds, hazelnuts)
1/2 cup SPLENDA® No Calorie Sweetener, granulated , granular
1/2 cup sour cream
2 eggs
1/2 tsp vanilla extract
2 tbsp powdered sugar , for dusting

1 Preheat oven to 350°F.
2 Lightly coat 9-inch springform pan with butter-flavored cooking spray.
3 In bowl of electric mixer, beat egg whites on high until stiff, glossy peaks form.
4 Microwave chocolate in microwave-safe bowl on high for 1- 2 minutes. Stir until smooth.
5 Scrape chocolate into medium size mixing bowl.
6 Stir in cocoa, nuts, Splenda, sour cream, eggs, and vanilla extract.
7 With spatula, fold in egg whites.
8 Spoon batter into prepared springform pan and gently smooth top.
9 Bake for 30 minutes. Remove from oven and let stand until cool.
10 Loosen edges of pan and remove cake. Cake will deflate.
11 Slice, dust with powdered sugar, and serve.