1. Sift almond flour and powdered sugar into a bowl to eliminate clumps and ensure a fine texture.

2. In a clean mixing bowl, whip the aged egg whites until foamy. Gradually add granulated sugar and continue beating until stiff, glossy peaks form. Mix in vanilla extract.

3. Gently fold the sifted dry ingredients into the meringue. The batter should flow like lava and form ribbons that disappear after 10–15 seconds.

4. Transfer the batter into a piping bag fitted with a round tip. Pipe evenly sized circles onto baking mats or parchment. Tap trays firmly to release air bubbles. Let them rest for 30–60 minutes until a skin forms.

5. Bake in a preheated oven at 300°F (150°C) for 14–16 minutes. Cool completely before removing.

6. For the buttercream: Beat butter until creamy. Add powdered sugar, vanilla, salt, and cream (if needed). Beat until smooth and fluffy.

7. Match up shells by size. Pipe buttercream onto one shell and gently sandwich with another. Let macarons mature in the fridge for 24 hours for best texture.