Sift powdered sugar and almond flour together twice.

Beat egg whites until foamy, gradually add cream of tartar and sugar, beating to stiff peaks.

Fold in green gel food coloring and sifted almond flour mixture until glossy.

Pipe tree shapes or circles onto baking sheets and tap to release air bubbles.

Rest piped batter at room temperature for 30-60 minutes.

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

Beat softened butter until fluffy. Mix in powdered sugar, vanilla, heavy cream, and salt, then fold in crumbled snack cakes.

Pair macaron shells, pipe filling onto one flat side, sandwich with another shell.

Optional: Melt white chocolate and drizzle over macarons, add decorations.

Refrigerate assembled macarons for at least 24 hours.