Diabetic Chocolate Flourless Cake

9 oz dark chocolate (Lindt Excellence 70% Dark is good. 2.25 bars is 9 oz.)
1/2 c butter
6 eggs
1/4 c sugar
Whipped cream (optional)

1. Melt chocolate in microwave. When it starts to melt, add stick of butter and melt until completely melted.
2. Get out 2 bowls for the eggs. In one bowl, put two whole eggs and four egg yolks. In another bowl, put 4 egg whites.
3. Beat egg whites for a minute or so on high. Add sugar and beat until dairy queen ice-cream type peaks form when you insert and remove a spoon.
4. Stir chocolate/butter into egg yolks bowl.
5. Add glob of egg whites to chocolate mixture, then fold in rest of egg whites by hand. Don't overmix.
6. Pour into greased 12" round pan or square casserole and bake at 350 for 30+ minutes. It is done when you jiggle the pan and the center doesn't jiggle. The top will be cracked and the cake will have risen a lot. It will fall again when you take it out of the oven.
7. Scoop out cake with spoon to serve! Add whipped cream if you want.