Sift the powdered sugar and almond flour together twice to ensure a lump-free mixture. In a clean bowl, beat the egg whites until frothy, then add cream of tartar. Gradually mix in granulated sugar while continuing to beat until stiff peaks form, showcasing a glossy meringue. Gently fold in the sifted almond flour mixture and green gel food coloring until the batter flows smoothly like lava.

Transfer the festive macaron batter into a piping bag fitted with a round tip. On lined baking sheets, pipe tree shapes or circles, creating uniform sizes for perfect sandwiches. After piping, lightly tap the sheets against the counter to release any trapped air bubbles. Allow the piped shells to rest at room temperature for 30-60 minutes until a skin forms.

Preheat your oven to 300°F (150°C) while your macarons rest. Bake one tray at a time for 14-16 minutes, turning the tray halfway through. They’re done when they have risen and their feet have formed.

In a mixing bowl, beat the softened butter until fluffy. Gradually mix in powdered sugar, then add cold heavy cream, vanilla extract, and a pinch of salt. Fold in the crumbled snack cakes until well combined.

Pair similar-sized macaron shells and pipe a generous amount of the filling onto the flat side of one shell. Sandwich with another shell, pressing lightly. Optionally, drizzle with melted white chocolate and add sprinkles.

Place the assembled macarons in an airtight container and refrigerate for at least 24 hours to meld flavors and soften textures.