Measure all ingredients correctly using a digital kitchen scale. Line two baking sheet pans with a baking mat.
Add egg whites and powdered food coloring to the mixing bowl of the stand mixer. Whisk on low speed.
Start adding sugar in a few parts. After that, change the speed in the mixer to medium and set up the timer for 15 minutes.
In the other mixing bowl, sift together almond flour, cocoa powder, and powdered sugar.
Add sifted dry ingredients to the French meringue and fold the batter using a spatula. Do not overfold! Check the batter every 5 folds. The batter is ready when it flows fast from the spatula.
Transfer the batter to the piping bag with a round tip.
Pipe macaron shells on the prepared baking mats. Hold the piping bag straight and apply pressure when you start piping, then stop when you reach the desired size of the macaron shell.
Lightly tap the baking tray to remove air bubbles. Use a toothpick or a baking needle to remove the bubbles from the piped macaron shells.
Let macaron shells rest (dry) on the countertop for about 15 minutes.
Meanwhile, preheat the oven to 300°F (150 °C).
Bake macaron shells in a preheated oven for 14-16 minutes. Baking time and temperature may be different, depending on your oven.
Remove the baking tray from the oven and let the macaron shells cool to room temperature before removing them from the mat.
Pair macaron shells of similar sizes before filling them.
How to Make Peppermint Mocha Ganache
In the saucepan, mix heavy cream, cocoa powder, glucose syrup, and peppermint extract. Bring the mixture to a boil, but do not boil.
Melt the chocolate in the microwave or using the double-boiler method.
Pour the hot mixture over the milk chocolate.
Emulsify with an immersion blender.
Add butter and emulsify again.
Transfer ganache into a flat container and cover with the plastic wrap "to contact".
Refrigerate ganache for a few hours. Ganache stabilizes fast.
How to Assemble Peppermint Mocha Macarons
When ready to assemble the macarons, transfer the ganache into a pastry bag fitted with a round piping tip.
Pipe ganache on the flat side of one macaron shell.
Sandwich a macaron with another macaron shell and press lightly. Make sure there is no ganache coming out from the sides of the macaron.
Repeat with the rest of the macarons.
Place assembled macarons in the flat container with a cover and refrigerate for 12-24 hours.