Preheat oven to 350 degrees F. Lightly butter (or use coconut oil) a round cake pan.
In a large metal bowl set over a pan of hot, not simmering, water (bottom of the bowl should not touch the water), combine the butter and both cocoa powders, stirring until melted and well blended. Stir in the vanilla extract and orange extract (if using). Remove from heat and set aside.
In a medium-size bowl, beat the egg yolks and maple sugar until very creamy. Set aside.
In the bowl of your electric mixer, beat egg whites with a pinch of salt until fairly stiff. Set aside.
In another large bowl, combine the chocolate/butter mixture with the beaten egg yolks until well blended. Fold in the beaten egg whites, blending gently with a spoon or rubber spatula. Pour chocolate mixture into the prepared cake pan.
Remove from oven and let the cake cool on a wire rack for 45 minutes. Torte will rise to a dome shape as it bakes, but will fall some as it cools on a rack. After cake has cooled, cover with plastic wrap and refrigerate until very firm, about 3 hours.
To Unmold: Run a thin metal spatula around the side of the cake and release the sides of the pan. The chocolate cake will store up to 2 weeks refrigerated.
When ready to serve, bring to room temperature. Cut into narrow wedges with a thin sharp knife that has been dipped in hot water.
Serve with whipped cream sweetened with maple sugar. Rebecca says, "Maple Sugar is interesting to use in whipped cream because right after whipping it you can taste the granulated maple sugar. But, after it sits in the refrigerator awhile, the granulated texture goes away and the cream is smooth".
Makes 12 to 16 servings.
Flourless Chocolate Cake Recipe: https://whatscookingamerica.net/rebeccawagner/flourlesschocolatetorte.htm