Preheat the oven to 350°.
Add the egg whites along with ½ of the sugar to a stand mixer with the whisk attachment and whip on high speed until stiff peaks are formed, about 6 to 7 minutes. Chill in the refrigerator.
Put the chocolate into a glass or metal bowl and cook over a double boiler until completely melted. Set aside.
Add the butter and remaining sugar to a stand mixer with the whisk attachment and whisk on high speed until light and fluffy, about 5 minutes.
Add in 1 egg at a time to the mixer until combined until all the eggs have been incorporated.
Remove the bowl from the stand mixer and fold in the almond flour until combined, then fold in the chocolate until combined.
Lastly, fold in the chilled meringue until combined.
Prepare a 10” springform pan with butter and cocoa powder.
Pour the batter into the prepared pan and bake at 350° 40 to 42 minutes.
Cool completely and dust with powdered sugar.