Aquafaba Macarons (Vegan)

Directions

1. Reduce the aquafaba: pour the chickpea water into a medium pot, and bring to a boil over medium heat. Reduce the heat so your chickpea liquid is simmering, and continue to simmer until it reduces by ⅓ (to about 1 1/2 cups / 325 g). Divide the aquafaba, reserving 1 ¼ cup / 270 g for the macaron shells, and 1 ¼ cups / 270 g for the buttercream. Cool completely. (Store extra aquafaba in an airtight container in the refrigerator or freezer - see headnote).
2. Line two baking sheets with parchment paper (use your flattest ones). Use a 1 ½ inch round cookie cutter to trace rounds onto the parchment paper. Trace the circles in rows, spacing each about ¾ inch apart from one another, staggering the rows to fit as many macarons onto the sheet as will comfortably fit (ideally, 24 per sheet). Turn the parchment paper over so the ink won’t touch the batter when you pipe onto the paper. Fit a pastry bag with a large round tip (such as 803/804/805).
3. Sift the almond flour, powdered sugar, and salt together into a medium bowl. Repeat 1-2 more times - you’re trying to eliminate clumps, combine the dry ingredients, and also aerate this mixture. (If any rogue clumps of almond flour remain that won’t fit through the strainer even when coerced, discard them.)
4. Make the macaron shells: place the aquafaba and cream of tartar in the bowl of an electric mixer fitted with the whip attachment. Whip on low speed until the mixture starts to become opaque, then raise the speed to medium and whip until it starts to gain volume. Start adding the sugar gradually, ultimately raising the speed to high once it is all incorporated and beating the aquafaba to stiff peaks, 4-6 minutes. Add the vanilla and mix to combine.
5. Remove the whipped aquafaba from the mixer. Add about half of the almond flour mixture to the bowl and start to mix with a silicone spatula to combine. It’s ok to mix the batter a bit more vigorously at this stage - you’re sort of “tempering” the batter with the dry ingredients, which will make it easier to incorporate the remainder. You’re also intentionally starting to the deflate the batter to get it close to the ideal texture.
6. Add the remaining almond flour mixture to the batter, and fold gently to incorporate with a silicone spatula. Move the spatula around the outside of the bowl in a circular motion, then cut through the center and repeat. Rotate the bowl as you fold to keep working with all the batter evenly. The goal is to end up with a batter the consistency of “lava” - it should hold it’s shape when dropped from the spatula but slowly spread and lose definition (thick but not so thick it holds any peaks).
7. Gently transfer the batter to the prepared piping bag (filling it just over halfway full). Pipe the batter onto the prepared baking sheets using the guides to keep them evenly sized. Hold the pastry bag parallel to the baking sheet and begin to apply pressure, allowing the batter to flow out of the tip into a fluid round. Stop applying pressure just before you reach the end of your guide. Repeat until the baking sheets are filled up, refilling the pastry bag as needed.
8. Gently tap the baking sheets on the countertop - this should smooth out the surface of the macaron and spread it slightly. If desired, use a needle or skewer to pop any visible bubbles on the surface of the macarons.
9. Let the macarons rest at room temperature until they form a skin on the surface, about 30 minutes-1 hour (it can take less time in a dry environment, longer in a more humid one). Towards the end of rest time, preheat the oven to 300°F with your oven rack in the center portion of the oven. (I bake one tray at a time because they are so finicky, but if your oven can handle it, you can bake both trays at once).
10. Bake the macarons until they have risen, forming a foot on the bottom, and the surface of the cookies is shiny, dry, and set, 18-20 minutes. Cool the macarons completely on the baking sheet. (The shells can be carefully stored in an airtight container, layers separated by pieces of parchment paper, and frozen for up to 3 months. When you’re ready, assemble the macarons using frozen cookies, then refrigerate overnight before serving.)
11. Make the aquafaba buttercream: bring a medium pot with about 1 inch of water to a simmer. In the bowl of an electric mixer (make sure it fits snugly on the pot without touching the water), whisk the 1 ¼ cup / 269 g aquafaba, cream of tartar, and sugar to combine. Continue to whisk this mixture until the sugar is fully dissolved, 2-3 minutes.
12. Transfer the mixer bowl to the stand mixer and whip until it forms stiff peaks and the bowl is no longer warm to the touch, 5-6 minutes.
13. With the mixer running on medium speed, start adding the vegan butter 1 tablespoon / 15 g at a time, allowing each addition to incorporate before adding the next. Continue until all of the butter is incorporated and the frosting is thick and smooth. Beat in the vanilla.
14. If the frosting is too loose, add powdered sugar 2 tbsp / 14 g at a time until it reaches a nicely pipeable consistency. Transfer to a pastry bag, fitted with a medium round or star tip.
15. When they are cool, gently peel the macarons off of the parchment paper. As you work, you can pair up the macarons with their closest match, flipping over half of the cookies.
16. Pipe a mound of filling into the center of the cookies that are flipped over, stopping just shy of the outside edge. Place it’s cookie pair on top and press down gently.
17. The cookies can be eaten immediately, but they are typically refrigerated overnight, which softens the cookie as it absorbs moisture from the filling. Transfer the cookies to an airtight container and refrigerate overnight. (The cookies can also be frozen in an airtight container for up to 3 months. Thaw in the refrigerator overnight before serving.)