For the Macaron Shells:

1. 1. Preheat your oven to 300°F (150°C) and line two baking sheets with parchment paper.
2. 2. In a bowl, sift together almond flour, powdered sugar, and cocoa powder until well combined.
3. 3. In a clean bowl, beat aged egg whites on medium speed until frothy. Gradually add granulated sugar while increasing speed until stiff peaks form.
4. 4. Gently fold the dry ingredients into the whipped egg whites until just combined; be careful not to deflate the mixture.
5. 5. Transfer the batter to a piping bag fitted with a round tip and pipe small circles onto prepared baking sheets, leaving space between each.
6. 6. Let the piped macarons rest for about 30 minutes until they form a skin. Bake for 15-20 minutes or until they lift easily from the parchment paper.

For the Chocolate Ganache Filling:

1. 1. Heat heavy cream in a small saucepan over medium heat until it begins to simmer.
2. 2. Pour hot cream over chopped dark chocolate in a bowl and let it sit for about 5 minutes. Stir until smooth and glossy.