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

Sift together the almond flour, powdered sugar, and salt in a mixing bowl.

Whip the aged egg whites on medium speed until frothy, then add granulated sugar while increasing speed to high until stiff peaks form.

Gently fold in the vanilla extract and green gel food coloring until evenly mixed.

Fold the sifted almond flour mixture into the meringue in three additions.

Pipe small circles about 1.5 inches in diameter onto the prepared baking sheets.

Let the piped macarons rest for 30-60 minutes until a skin forms.

Bake for 15-18 minutes, rotating halfway through to ensure even baking.

Cool the macarons completely on the sheets before transferring to a wire rack.

Beat softened butter until creamy, then gradually add sifted powdered sugar and heavy cream until fluffy. Stir in additional vanilla extract.

Pair macarons by size, pipe buttercream on one shell, and sandwich with the other.

Decorate with edible glitter or sprinkles, and add red candies or fruit chews if desired.