In a mixing bowl, combine the almond flour, powdered sugar, and cocoa powder. Sift this mixture through a fine mesh sieve.

Take half of your room temperature egg whites and mix them with the dry mixture, forming a thick almond paste.

Heat granulated sugar and water in a saucepan to create a syrup while whipping remaining egg whites until foamy.

Slowly pour the sugar syrup into the whipped egg whites to make the Italian meringue until stiff peaks form.

Fold a small amount of the meringue into the almond paste, then gently fold in the remaining meringue until smooth.

Pipe small rounds of the batter on a lined baking sheet, tap to release air bubbles, and let rest for 20-30 minutes.

Preheat the oven to 320°F (160°C) and bake macaron shells for 12-15 minutes until they rise and firm up.

Prepare ganache by heating heavy cream and pouring over semisweet chocolate. Stir until smooth and refrigerate to thicken.

Once shells are cool, pipe ganache onto one macaron shell and sandwich it with another; chill for best flavor before serving.