Preheat oven to 160 degrees C fan forced (180 non fan forced)/320 degrees F fan forced (360 degrees F non fan forced)
Use a 20 cm springform tin, and lightly spray with oil, then line the base and sides with baking paper.
Melt the chocolate, butter, and orange zest in a saucepan over a low heat, until the chocolate is melted and silky, then remove from stove and set aside to cool. Stir in the coffee and vanilla.
With an electric beater, beat the egg yolks and granulated stevia/sweetener until it gets thick and creamy like.
Delicately fold in the chocolate mixture from the saucepan using a big spoon
Delicately fold in the almond meal to the chocolate mixture.
Clean and dry electric beaters, then beat the egg whites until they are white and foamy. Delicately fold in half the egg whites at a time to the chocolate mixture.
Pour in the chocolate batter into the spring foam tin and bake in preheated oven for 50 minutes. Once timer has gone off, let cake cool in the pan for 15 to 20 minutes before removing.