Step 1: Prepare Your Ingredients and Tools

1. Sift the almond flour and powdered sugar together into a large bowl. This step is crucial to ensure smooth macaron shells. Discard any large lumps.
2. Separate the egg whites from the yolks. Ensure no yolk gets into the whites, as this can prevent them from whipping properly.
3. Line your baking sheets with parchment paper or silicone mats.

Step 2: Whip the Egg Whites

1. In a clean, dry bowl, beat the egg whites on medium speed until foamy.
2. Gradually add the granulated sugar, one tablespoon at a time, while continuing to beat.
3. Increase the speed to high and whip until stiff peaks form. The meringue should be glossy and hold its shape.
4. Add vanilla extract and gel food coloring (if using) and mix gently.

Step 3: Fold in the Dry Ingredients

1. Add the sifted almond flour and powdered sugar mixture to the meringue in two batches.
2. Using a spatula, gently fold the mixture until it reaches a “lava-like” consistency. The batter should flow smoothly and form ribbons that disappear back into the mixture after about 10 seconds.

Step 4: Pipe the Macaron Shells

1. Transfer the batter into a piping bag fitted with a round tip.
2. Pipe small, even circles (about 1.5 inches in diameter) onto the prepared baking sheets.
3. Tap the baking sheets firmly on the counter a few times to release any air bubbles. Use a toothpick to pop any remaining bubbles.

Step 5: Rest the Macaron Shells

1. Let the piped shells sit at room temperature for 30-60 minutes, or until a skin forms on the surface. You should be able to lightly touch the shells without the batter sticking to your finger.

Step 6: Bake the Macarons

1. Preheat your oven to 300°F (150°C).
2. Bake the macarons for 15-18 minutes, rotating the tray halfway through for even baking.
3. Let the shells cool completely on the baking sheet before removing them.

Step 7: Prepare the Filling

1. In a bowl, beat the softened butter until creamy.
2. Gradually add the powdered sugar, followed by the heavy cream and vanilla extract. Mix until smooth and fluffy.
3. Add any additional flavorings or colors as desired.

Step 8: Assemble the Macarons

1. Pair up the macaron shells by size.
2. Pipe a small amount of filling onto the flat side of one shell and gently press the other shell on top.
3. Twist slightly to spread the filling evenly.