Step 1

Prep your pan. Preheat your oven to 300°F (150°C). Butter the bottom and sides of a 9-inch springform pan. You can also line the bottom of the springform pan with parchment paper (on top of the butter) for easy removal.

Step 2

Make the chocolate mixture. Add the chocolate and butter to a large glass bowl and melt over a double-boiler, stirring until fully melted. Alternatively, you can slowly heat the chocolate and butter in 20-second increments in the microwave. Remove the bowl from the double-boiler (or microwave) and let cool to room temperature.

Step 3

Whip the egg whites. While the chocolate is cooling, add the egg whites to a large bowl and beat on medium-high until soft peaks form. Slowly add the coconut sugar while beating, about one tablespoon at a time, until fully incorporated. Set aside.

Step 4

Mix the chocolate and eggs yolks. To the melted and now room-temperature chocolate, add the egg yolks and espresso powder and stir together. Make sure the chocolate is cooled to room temperature, otherwise, you'll end up with scrambled eggs in your chocolate.

Step 5

Mix the egg whites into the chocolate. Add ⅓ of the egg whites to the chocolate, then stir to combine and lighten the chocolate mixture. Gently fold in the remaining egg whites, trying not to deflate the mixture too much.

Step 6

Bake the cake. Pour the batter into the springform pan and bake for 45 minutes. The cake will rise to the top of the springform pan while baking but will deflate once cooled.

Step 7

Cool and serve. Let the cake cool completely, then remove from the springform pan. Dust with cacao powder before serving.