In a medium bowl, sift together almond flour, caster sugar and cocoa powder twice. Set aside.

In a large mixing bowl with whisk attachment, beat the egg whites on medium speed until foamy. Add cream of tartar and continue to beat. Slowly add sugar one tablespoon at a time. Increase the speed to medium high and beat until hard peaks form.

Sift the almond flour mixture over the whipped egg whites. Gently fold the mixture running the spatula clockwise from the bottom, up around the sides and cut the batter in half. The batter will look very thick at first, but it will get thinner as you fold. Every so often test the batter to see if it reached the right consistency.

While macarons are cooling, prepare the ganache filling. Heat the heavy cream in the microwave for a minute. In a medium bowl, put the chocolate chips and pour hot cream over the chocolate. Let it stand for a minute or two and then stir until smooth. Stir in Nutella cool it in the fridge to thicken.