Sift almond flour and powdered sugar together.

Whip egg whites until frothy, gradually adding granulated sugar until stiff peaks form.

Fold in peppermint extract and optional coloring.

Gently fold dry ingredients into meringue until batter flows like lava.

Pipe batter onto a lined baking sheet, tap to release air bubbles.

Let shells rest 30–60 minutes until a skin forms.

Preheat oven to 300°F (150°C) and bake 15–18 minutes.

Beat butter, powdered sugar, cream, salt, and peppermint extract until creamy.

Pipe filling onto one shell and sandwich with another. Sprinkle crushed candies if desired.

Store in an airtight container for 24 hours before serving.