Line two large baking sheets with parchment paper or silicone mats. Have a piping bag fitted with a 1/2-inch round tip ready.

In a medium bowl, thoroughly whisk together the sifted almond flour and powdered sugar. Sift this mixture one more time to ensure no lumps remain.

In a very clean, dry bowl of a stand mixer, combine the egg whites and cream of tartar. Whip on medium speed until foamy.

Gradually add the granulated sugar, about 1 tablespoon at a time.

Increase speed to high and whip until stiff, glossy peaks form. Add vanilla and food coloring in the final moments of whipping.

Add about one-third of the dry ingredients to the meringue. Gently fold using a large spatula, scraping from the bottom up and turning the bowl.

Add the remaining dry ingredients and continue folding until the batter flows like lava and forms a thick ribbon.

Transfer the batter to the prepared piping bag. Pipe 1.5-inch rounds onto the lined sheets, spacing them about 1 inch apart.

Firmly tap the baking sheets on the counter 3-4 times to release any air bubbles.

Let the piped shells sit at room temperature for 30-60 minutes until they form a dry skin.

Preheat your oven to 300°F (150°C). Bake one sheet at a time for 15-18 minutes, rotating halfway through.

The shells are done when they don’t wiggle when gently touched.

Let the shells cool completely on the baking sheet before attempting to remove them.