Sift together powdered sugar and almond flour in a large bowl.

Beat egg whites until foamy, then gradually add cream of tartar and granulated sugar until stiff peaks form.

Gently add green gel food coloring to the egg whites and fold until blended.

Fold the dry mixture into the whipped egg whites until combined.

Pipe tree shapes on lined baking sheets and tap gently to release air bubbles.

Allow piped macarons to rest at room temperature for 30-60 minutes until a skin forms.

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

Let shells cool for about 10 minutes on the baking sheet, then transfer to a wire rack.

Prepare the filling by beating butter until fluffy, then adding powdered sugar, heavy cream, vanilla, and crumbled snack cakes.

Assemble the macarons by pairing shells and piping filling onto one side.

For decoration, drizzle with melted white chocolate and sprinkle with red and green sprinkles.

Refrigerate assembled macarons for at least 24 hours before serving.