Preheat the oven to 350℉. Line a 9-inch springform pan or regular cake pan with a circle of parchment paper. Spray with nonstick cooking spray and set aside.
Melt the butter in a large saucepan set over medium heat. Reduce the heat to medium-low and add the chocolate. Stir constantly until the chocolate is melted, glossy, and smooth. Remove from the heat. Whisk in 1/4 cup coconut sugar, maple syrup, coffee, cocoa powder, orange zest, and salt. Set aside to allow to cool.
Meanwhile, set out two large mixing bowls, or one mixing bowl and a stand mixer fitted with the whisk attachment. Carefully separate the yolks from the whites, placing the yolks in the bowl and the whites in the stand mixer (if using). Set aside.
Using a stand mixer or electric hand mixer, whip the egg whites on high speed. Once the whites have thickened and look opaque, add the remaining 1/2 cup coconut sugar. Continue to whip the eggs for about 4 minutes until they are fluffy, glossy, and a pale tan. The mixture will be a bit shiny.
Meanwhile, temper the egg yolks by adding about 1 tablespoon of the chocolate mixture to the egg yolks and whisk so that the eggs don’t curdle. Slowly pour the chocolate mixture into the bowl with the egg yolks and stir vigorously. It should be thick like a brownie batter.
Use a rubber spatula to carefully fold the egg whites into the chocolate mixture. This is important to do slowly so that you do not deflate the eggs. Carefully transfer the mixture into the prepared cake pan. Bake until the cake is puffed and just set, 35 to 40 minutes. Remove from the oven and allow to cool in the pan for 10 minutes. During this time, it will crack and deflate.
To serve, lift the cake out of the pan. Garnish the cake with powdered sugar, if using, and serve with fresh raspberries, vanilla ice cream, or whipped cream, if desired. Enjoy!