Begin by sifting the powdered sugar and almond flour together twice in a large mixing bowl.

In a clean, dry mixing bowl, beat the egg whites on medium speed until foamy. Gradually add the cream of tartar, then the granulated sugar until stiff peaks form.

Gently add in green gel food coloring to the meringue and mix until the color is uniformly distributed.

Fold the almond flour mixture into the meringue until the batter flows like thick lava.

Transfer the batter into a piping bag and pipe tree shapes or circles onto lined baking sheets.

Allow the piped macaron shells to rest at room temperature for 30-60 minutes.

Preheat your oven to 300°F (150°C) and bake the macarons for 14-16 minutes.

Let the macarons cool completely on the baking mats.

In a mixing bowl, beat the softened butter until fluffy. Gradually add powdered sugar, vanilla extract, heavy cream, and salt. Mix until smooth, then fold in the crumbled snack cakes.

Pipe a dollop of filling onto the flat side of one macaron shell and sandwich with another shell.

For an optional decoration, melt white chocolate, drizzle over the macarons, and sprinkle with festive sprinkles.