Line your baking tray with parchment paper or a silicone mat. Prepare piping bag with a 1 cm round tip.

Sift almond flour and powdered sugar together into a bowl. Discard any large bits.

In a separate clean bowl, beat the egg whites on medium speed until foamy. Gradually add the granulated sugar, then beat on high until stiff, glossy peaks form (about 3-4 minutes). Add food coloring if desired and mix just until evenly colored.

Gently fold the almond flour mixture into the egg whites with a spatula. Mix just until it flows like thick lava and falls from the spatula in a ribbon.

Transfer the batter to your piping bag. Pipe 24 even rounds (about 3-4 cm wide) onto your baking tray, spaced 2-3 cm apart.

Firmly tap the tray on the countertop a few times to release air bubbles. Let the macarons sit at room temperature for 30-40 minutes, until the tops are dry to the touch.

Preheat oven to 150°C (300°F). Bake for 14 minutes. The macarons are done when they have risen with feet, and can be gently nudged off the baking mat.

Cool completely on the tray before removing.

For the buttercream, beat the softened butter until creamy. Add powdered sugar, heavy cream, and vanilla extract. Beat until smooth and fluffy.

Pipe a small amount of buttercream onto half the cooled macaron shells. Sandwich with the remaining shells.

Let assembled macarons mature in the fridge for 24 hours before serving for best texture.

Store macarons in an airtight container in the fridge for up to 5 days.