Step 1: Prepare the Dry Ingredients

Sift the almond flour and powdered sugar into a large mixing bowl. Discard any large bits that remain to ensure a smooth macaron shell.

Step 2: Make the Meringue

Whip the egg whites in a clean, grease-free bowl with an electric mixer on medium speed until foamy.

Add the granulated sugar gradually and increase the speed to medium-high, beating until stiff, glossy peaks form. Add food coloring if desired.

Step 3: Fold the Batter (Macaronage)

Fold the dry ingredients into the meringue gently, using a spatula. Use a circular motion, scraping from the bottom and pressing the mixture against the sides of the bowl. Repeat until the batter flows in thick ribbons and can form a "figure 8" when lifted with a spatula.

Step 4: Pipe the Macarons

Transfer the batter to a piping bag fitted with a round tip. Pipe small circles (about 1 inch) onto a baking sheet lined with parchment paper or a silicone mat, spacing them about 1 inch apart.

Tap the baking sheet firmly against the counter a few times to release any air bubbles. Let the piped macarons rest for 30-60 minutes until the tops form a "skin" (they should not stick to your finger when lightly touched).

Step 5: Bake

Preheat the oven to 300°F (150°C).

Bake for 15-18 minutes, rotating the pan halfway through. The macarons are ready when they easily lift off the baking mat and have a smooth, dry surface with a “foot” at the base. Let them cool completely before removing.

Step 6: Make the Buttercream Filling

Cream the butter with an electric mixer until smooth. Add powdered sugar gradually and mix until light and fluffy.

Add vanilla extract and enough heavy cream or milk to achieve a smooth, pipeable consistency.

Step 7: Assemble the Macarons

Pipe a small amount of filling onto the flat side of one macaron shell, then sandwich with another shell. Repeat for the remaining macarons.

Refrigerate the macarons for at least 24 hours for the best texture and flavor. Let them come to room temperature before serving.