Preheat oven to 350° F.
Grease a 8-9 inch springform pan and wrap the bottom with foil to prevent leaking.
Melt the chocolate and butter together. Set aside.
Whisk egg yolks and half of the sugar together until pale and thick.
Stir in the chocolate mixture, espresso, almond flour and salt.
Using a stand mixer with the whisk attachment, beat the egg whites and remaining sugar on high until soft peaks form.
Gently fold a third of the whites into the chocolate batter. Fold in the rest, using two more increments.
Pour into the pan and smooth the top.
Bake for 35-45 minutes, depending how fudgy you like your torte.
Cool to room temperature, and then refrigerate for four hours, or until completely chilled.
Sift cocoa powder on top, and serve cold or at room temperature.
