Remove egg whites from the fridge and let them come to room temperature (about 30 minutes).

Sift together almond flour and powdered sugar into a large bowl to remove any lumps.

In a clean metal mixing bowl, beat egg whites on medium speed until foamy. Gradually add granulated sugar and continue beating until stiff peaks form. Stir in vanilla extract and food coloring if desired.

Gently fold the dry ingredients into the meringue in two batches. Use a spatula to press out large air bubbles—aim for a glossy, flowing batter.

Transfer the batter into a pastry bag fitted with a round tip. Pipe 1-inch rounds onto a baking sheet lined with parchment paper or a silicone mat.

Tap the baking sheet on the counter to release air bubbles. Let the piped cookies rest at room temperature for 30–60 minutes, until a thin crust forms on top.

Preheat your oven to 300°F (150°C). Bake the macaroons for 15–18 minutes. They’re done when they easily peel away from the parchment and have their signature “feet.”

Allow the cookies to cool completely on the baking sheet.

Pair up similar-sized shells and fill each sandwich with about 1 tablespoon of buttercream. Press gently to spread.

For best texture, refrigerate the filled macaroons in an airtight container for 24 hours before serving.