Preheat your oven to 150°C (300°F) and line two baking trays with parchment paper.

Combine icing sugar, almond meal, and Dutch-process cocoa powder in a food processor and sift into a mixing bowl.

Whisk egg whites in a stand mixer and cook caster sugar and water in a saucepan until it reaches 118°C (244°F). Pour into egg whites while whisking.

Continue whisking until achieving medium peaks, about 5-7 minutes. The meringue should be shiny and hold its shape.

Fold the sifted dry ingredients into the meringue carefully to achieve the right consistency.

Transfer the batter into a piping bag and pipe circles onto prepared trays using pencil marks as guides.

Bake for 15-18 minutes until the shells are firm and cool completely on the trays.

Heat heavy cream, orange zest, and salt until just scalded. Pour over chopped dark chocolate and stir until smooth.

Once cooled, pipe ganache between two macaron shells and refrigerate for at least 24 hours.