1. Start by preparing the macaron shells:
Preheat your oven to 140°C (this is an average temperature, adjust according to your oven*)
2. Blend the almond powder and powdered sugar in a blender until finely ground, then sift the mixture
3. Divide this mixture into two separate bowls. In one of the bowls, add the tablespoon of unsweetened cocoa powder and mix well
4. In each of the two bowls, add 37g of egg whites without mixing
5. In the bowl of your stand mixer, weigh 74g of egg whites
6. In a small saucepan with a thick bottom, mix the water and granulated sugar with a spatula, then heat over medium heat
7. As soon as the syrup reaches 110°C, start whisking your egg whites at high speed
8. When the thermometer reads 118°C, remove the saucepan from the heat, reduce the speed of your mixer (medium speed), and pour the cooked sugar onto the beaten egg whites
9. Incorporate half of the meringue (about 133g) into one of the bowls with the powdered sugar/almond powder/egg whites mixture, and the other half into the second bowl
10. Once you have poured all the syrup, continue beating the mixture at high speed for about a minute to cool the meringue. It should be smooth, shiny, and form a "bird's beak" when the whisk is lifted, as it forms a slight peak at the end of the whisk
11. Incorporate half of the meringue (about 133g) into one of the bowls with the powdered sugar/almond powder/egg whites mixture, and the other half into the second bowl
12. Now you will macaronage the two mixtures one after the other. Macaronage involves mixing with a spatula, scraping the sides and bottom while turning and lifting the mass, then folding it back onto the center. You should obtain a shiny, homogeneous, semi-liquid mixture that forms a ribbon when it falls. The consistency of the batter should not be too liquid, as the shells may spread too much during piping, nor too thick, as the macarons will be too hard and have an unattractive pointy top.
13. Transfer the two mixtures into piping bags fitted with 8mm diameter tips, and pipe rounds in a staggered pattern onto a baking sheet lined with parchment paper
14. Tap the baking sheets on the countertop to smooth out the shells
15. Sprinkle crushed hazelnuts on the white shells (optional)
16. Bake the shells for about 12 minutes (this is an average time, adjust according to your oven*)
17. As soon as they come out of the oven, slide the parchment paper onto the countertop to stop the cooking process
18. Let the shells cool completely before gently removing them from the parchment paper
19. Prepare the Schoko-Bons ganache:
Melt the Kinder Schoko-Bons, heavy cream, and butter over low heat
20. Mix well and once the mixture is smooth, transfer it to a container
21. Cover with plastic wrap and refrigerate (the ganache is ready to be used when it has cooled and thickened enough)
22. Arrange your macaron shells on a baking sheet and fill them with the ganache using a piping bag
23. Sandwich each macaron with an unfilled shell
24. Ideally, refrigerate for 24 hours before serving