Mix the powdered sugar and almonds. Sift the flour and powdered sugar mixture at least 2 times until there is only a fine almond and powdered sugar flour left.
Weigh the egg whites exactly (important for the consistency!) And beat until stiff with the mixer. As soon as the egg white becomes frothy, pour in the sugar and keep beating until the tips stop. Now add the paste food coloring as desired and continue beating for another 1 minute. Put the egg whites in a large bowl, add the almond and powdered sugar mixture in 3 steps, carefully fold in with a spatula.
Fill the piping bag with a perforated nozzle (for a precise round shape) with the macarons mass. Cover the baking sheet with parchment paper. Now use the piping bag to put approx. 2 cm wide (approx. The size of a 2 euro coin) blobs on the tray, making sure to leave some space, as the macarons will still diverge a little, now let the tray stand for 30 minutes. Shortly before the 30-minute rest period is over, the oven is preheated to 150 degrees top / bottom heat. Put the tray with the macarons in the preheated oven, turn it down to 145 degrees and bake the macarons for about 12-14 minutes. Take out the macarons and pull them together with the baking paper from the tray onto the cold work surface and let them cool down.
Meanwhile, for the ganache, finely chop the white chocolate and place in a bowl. Bring the cream to the boil while stirring, then pour over the chocolate. Let stand for 2 minutes, then stir well until there are no lumps left. Let the ganache cool down, then chill for at least 1 hour.
Use the whisk of the mixer to beat the cold ganache until it becomes firmer and lighter. Color with fat-soluble food coloring or leave to light. Put the ganache in a piping bag with any nozzle. Remove the macarons halves from the baking paper. Sprinkle a dollop of ganache on the bottom of each half of the macarons, then put a second lid on and press down gently.
Stuffed macarons can be stored in a cool place for about 5-7 days.