Preheat oven to 350 degrees F. Butter a shallow 2 qt. baking dish and coat with the 1 TBSP powdered sucanat. Set aside.
Get out a roasting pan that is big enough to hold your 2 qt. baking dish. Fill a tea kettle of saucepan with water and place over high heat to bring to a boil.
Combine egg yolks and 1/3 cup powdered sucanat in a mixing bowl. Beat vigorously with a wire whisk for one minute. Mixture should thicken and get lighter in color.
Whisk melted (not hot) chocolate into the egg mixture and set aside.
With an electric mixer, beat egg whites with salt until soft peaks form.
Whisk 1/3 of the egg white mixture into the chocolate mixture. (If using the orange zest, add at this time.) Fold the remaining egg whites into the chocolate mixture just until combined.
Transfer the batter to the 2 qt. baking dish. Place the baking dish in the roaster and then fill the roaster with the boiling water so that the water comes 1 inch up the side of the baking dish. Be careful not to pour any water into the cake pan itself.
Bake 25-30 minutes or until just set. The middle should still be slightly jiggly. Allow to cool for 5 minutes.
Remove the baking dish from it's water bath in the roaster and serve immediately while warm or allow to completely cool and then serve chilled from the refrigerator. Serve with freshly whipped cream.