Prepare the Macaron Shells

1. Prep Baking Sheets: Line two baking sheets with parchment paper or silicone baking mats.
2. Sift Dry Ingredients: In a large bowl, sift the powdered sugar and almond flour together to remove any lumps.
3. Whisk Egg Whites: In a separate bowl, whisk the egg whites with the cream of tartar on medium speed until soft peaks form.
4. Add Sugar: Gradually add the granulated sugar, continuing to whisk until stiff peaks form and the meringue is glossy.
5. Fold in Dry Ingredients: Gently fold in the sifted almond flour and powdered sugar mixture into the meringue, a little at a time, until fully incorporated. Be careful not to deflate the meringue.
6. Add Food Coloring: Divide the batter into separate bowls, adding food coloring to each if you’re making multiple colors for your macarons.
7. Pipe the Macarons: Transfer the batter into a piping bag with a round tip and pipe small, uniform circles onto the prepared baking sheets.
8. Rest the Macarons: Allow the macarons to sit at room temperature for 30-60 minutes to form a skin. This step is crucial for getting the signature “feet” on your macarons.
9. Bake: Preheat the oven to 300°F (150°C). Bake the macarons for 15-20 minutes, or until they are firm to the touch and easily peel away from the parchment paper. Let them cool completely before filling.

Make the Buttercream Filling

1. Whip Butter: In a medium bowl, beat the softened butter until smooth and creamy.
2. Add Powdered Sugar: Gradually add the powdered sugar, 1/2 cup at a time, and continue to beat until smooth.
3. Add Cream and Vanilla: Mix in the heavy cream and vanilla extract until the buttercream is light and fluffy.
4. Add Food Coloring: Divide the buttercream into bowls and color each portion with food coloring as desired for your tree decorations.

Assemble the Macaron Christmas Tree

1. Pair the Macarons: Pair the macaron shells that are of similar size to ensure a uniform look for your tree.
2. Fill the Macarons: Pipe a dollop of buttercream onto the flat side of one macaron shell, then sandwich with the matching shell.
3. Build the Tree: Start at the bottom of your serving tray and place the largest macaron at the base. Continue stacking smaller macarons in a pyramid shape, securing each layer with a little buttercream. Use a small amount of buttercream between each layer to hold the macarons in place.
4. Decorate: Once the macaron tree is assembled, decorate with sprinkles, edible glitter, or mini candy decorations. You can also add a small candy star at the top for extra flair.

Chill and Serve

1. Chill (Optional): Chill the assembled tree for 30 minutes to set the buttercream.
2. Serve: Once chilled, your Macaron Christmas Tree is ready to be served and admired!