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

Beat the egg whites at medium speed until foamy. Gradually add granulated sugar and cream of tartar, beating until stiff peaks form (about 5-7 minutes).

Gently fold in green gel food coloring, then gradually incorporate the sifted almond flour mixture until the batter flows like lava.

Transfer the batter to a piping bag and pipe tree shapes on a lined baking sheet. Tap the baking sheet to release air bubbles.

Let the piped shells rest at room temperature for 30-60 minutes until dry to the touch.

Preheat oven to 300°F (150°C) and bake the shells for 14-16 minutes. Cool completely on parchment paper.

Beat unsalted butter until fluffy, then mix in powdered sugar, vanilla, heavy cream, salt, and crumbled snack cakes.

Pipe filling onto one macaron shell, sandwich with another, and optionally drizzle with melted chocolate and sprinkles.

Refrigerate the assembled macarons for at least 24 hours to mature the flavors.