Preheat your oven to 300°F (150°C) and line two baking sheets with parchment paper or silicone mats.

Sift together the powdered sugar and almond flour into a mixing bowl, repeating this process twice for a smooth texture.

In a clean mixing bowl, add room-temperature egg whites and beat on medium speed until foamy, about 1-2 minutes.

Gradually sprinkle in the granulated sugar and whip until stiff peaks form, about 5-7 minutes.

Gently incorporate the green gel food coloring using a spatula for a smooth blend.

Slowly fold the sifted almond flour and powdered sugar mixture into the whipped egg whites until the batter flows smoothly.

Transfer the macaron batter into a piping bag fitted with a round tip and pipe tree shapes or circles onto prepared baking sheets.

Let the piped macarons rest at room temperature for 30-60 minutes.

Place the trays in the oven and bake for 14-16 minutes, rotating halfway through.

Allow the macarons to cool completely on the mats before removing them.

Beat softened unsalted butter until fluffy, about 2-3 minutes. Mix in powdered sugar, heavy cream, vanilla extract, and a pinch of salt until smooth.

Fold in the crumbled snack cakes into the filling mixture.

Pair similar-sized macaron shells together and pipe a dollop of filling onto one half. Sandwich with the other shell.

Melt white chocolate and drizzle over macarons; sprinkle with edible decorations if desired.

Store assembled macarons in an airtight container in the refrigerator for at least 24 hours before serving for best flavor.