1️⃣ Prep your pans & ingredients: Line 2 baking sheets with parchment or silicone mats. Sift almond flour & powdered sugar together into a bowl.

2️⃣ Make the meringue: In a clean bowl, whip egg whites & cream of tartar on medium until foamy. Gradually add granulated sugar & keep whipping until stiff, glossy peaks form. Beat in vanilla & food coloring, if using.

3️⃣ Macaronage: Gently fold the dry mixture into the meringue, about 50 strokes. Batter should flow in thick ribbons & settle back after 10–15 seconds.

4️⃣ Pipe & rest: Transfer batter to a piping bag fitted with a round tip. Pipe 1.5-inch circles on your prepared pans. Tap pans firmly to pop air bubbles. Let sit 30–60 minutes, until tops feel dry.

5️⃣ Bake: Bake at 300°F for 15–17 minutes, rotating halfway. Cool completely before filling.

6️⃣ Make the buttercream: Beat butter until creamy. Add powdered sugar, vanilla, salt, and cream and whip until fluffy.

7️⃣ Assemble: Pipe a dollop of buttercream onto half the shells, then sandwich with remaining shells.