Steps

• To make the CHRISTMAS MACARONS, place the almond flour and powdered sugar in a food processor.
  Pulse in short bursts, avoiding overheating the almonds and releasing their oil, which in contact with the sugar would form grains.
  The final result should be a fine powder.
  Then pass the obtained powder through a sieve. This is the most tedious and lengthy phase of the preparation, but it is essential.

• Place the egg whites (kept at room temperature for at least 6 hours) in a bowl and whip them to stiff peaks, adding the granulated sugar in three additions so that the meringue gains structure and becomes glossy and firm.
  
  MACARONAGE
  Fold in half of the dry mixture slowly with a spatula from the bottom up, taking care not to deflate the batter.
  Add the powdered food coloring and incorporate.

• Add the remaining dry mixture, gently folding it in without deflating the batter.
  You should obtain a thick batter that, when it falls from the spatula, looks silky.
  Once the batter is ready, let it rest for 20 minutes and transfer it into a piping bag.
  Line baking sheets with parchment paper and, using a round cookie cutter as a guide, lightly draw circles with a pencil about 4 cm (approximately 1 9/16 in) in diameter, spaced apart. Alternatively, you can use a silicone macaron mold.
  Pipe a mound of batter into the center of each circle without completely covering the drawn outline. Tap the baking sheets gently three times so the batter levels.

• Place the trays near an open window or in a ventilated place and let them dry for 30 minutes so that a skin forms on the surface.
  Bake one tray at a time in a preheated, conventional oven at 145°C (293°F) for 12–14 minutes. When you see the classic “foot” beginning to form—after about 5 minutes—open the oven for 2 seconds to let the humidity escape, then close it and finish baking.
  Once baked, leave them in the oven with the door open for 2 minutes, then remove and let them cool completely on a cool surface.

• Once cool, gently detach them from the parchment paper, helping with a smooth-edged spoon if necessary. Be careful, as they are very delicate.

• For the CHOCOLATE GANACHE, heat the cream without bringing it to a boil, then remove from the heat and add the chopped chocolate.
  Whisk until you obtain a smooth sauce.
  Transfer it to a bowl, cover with cling film pressed onto the surface and let it cool to room temperature.
  Place the ganache in the fridge for at least 6 hours. When well chilled, whip it with electric beaters until it becomes lighter and fluffy.

• Put the ganache into a piping bag fitted with a star tip and pipe a dollop of cream in the center of each macaron shell. Close with another shell and once all the Christmas macarons are assembled, refrigerate them. If you want to make them even more festive, you can decorate them with an icing made from 40 g of powdered sugar (about 1/3 cup) and 2 teaspoons of cold water.