Prepare the Macaron Shells

1. Sift Dry Ingredients: In a bowl, sift together powdered sugar and almond flour to remove lumps and ensure a smooth batter.
2. Whip Egg Whites: In a clean mixing bowl, beat the egg whites until they start to foam. Gradually add the granulated sugar, continuing to beat until stiff peaks form.
3. Add Color and Flavor: Gently fold in the vanilla extract and red gel food coloring until the desired color is achieved.
4. Incorporate Dry Ingredients: Carefully fold the sifted powdered sugar and almond flour mixture into the egg whites until fully combined and the batter flows smoothly.
5. Pipe the Shells: Transfer the macaron batter to a piping bag fitted with a round tip. Pipe small circles (about 1.5 inches in diameter) onto a parchment-lined baking sheet, spacing them about 1 inch apart.
6. Rest the Shells: Let the piped macaron shells sit at room temperature for 30-60 minutes until a skin forms on the surface. This will help prevent cracks during baking.
7. Preheat the Oven: Preheat your oven to 300°F (150°C).

Bake the Macaron Shells

1. Bake: Bake the macarons for 15-20 minutes, or until they have risen and formed feet. They should not be sticky when touched.
2. Cool Completely: Remove the macarons from the oven and let them cool completely on the baking sheet before transferring to a wire rack.

Make the Buttercream Filling

1. Cream Butter: In a mixing bowl, beat the softened butter until creamy.
2. Add Powdered Sugar: Gradually add the powdered sugar, mixing until combined.
3. Add Cream and Vanilla: Add the heavy cream and vanilla extract, beating until the mixture is fluffy and smooth.
4. Transfer Filling: Place the buttercream in a piping bag for easy filling.

Assemble the Macarons

1. Pair Shells: Match up the macaron shells in pairs of similar sizes.
2. Fill the Macarons: Pipe a small amount of buttercream onto the flat side of one shell in each pair, then gently press the matching shell on top to create a sandwich.
3. Decorate as Santa: Use edible gel icing to create Santa’s eyes, mouth, and buttons on the macaron tops. Use a little extra buttercream to mimic the fur on his hat if desired.