Sift together the powdered sugar and almond flour in a large bowl twice to achieve a fine texture.

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

Add green gel food coloring and fold in the sifted mixture until a smooth batter forms.

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

Tap trays firmly on the counter to eliminate air bubbles and let macarons rest at room temperature for 30-60 minutes.

Preheat oven to 300°F (150°C) and bake one tray at a time for 14-16 minutes.

Cool macarons on baking sheets for 5 minutes, then transfer to a wire rack to cool completely.

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

Pair similar macarons and pipe filling between them, gently sandwiching together.

Optional: Melt white chocolate and drizzle over macarons, then sprinkle with red and green sprinkles.