In a small saucepan, heat the sugar on low heat until it’s completely melted, swirling the pan gently every 20 seconds or so. Remove from heat immediately and stir in butter. The mixture will violently bubble. You’re doing it right. Next, pour in the heavy cream and sea salt. Stir until everything is combined. Pour into small bowl or cup and allow to cool completely before using.
make the macarons
Using a fine mesh strainer, sift the almond flour, powdered sugar, and chai spice into a medium bowl. Sift the mixture again two more times. You may be left with small almond granules each time you sift. Toss these out after each sifting.
In a standing mixer using a whisk attachment (or mixing bowl with a hand mixer), whip the egg whites on medium-high speed for about 2 minutes, until soft peaks form. Slowly add in granulated sugar and cream of tartar, continuing to beat for 1-2 minutes more until stiff peaks form. The egg whites should be foamy and firmly hold their shape.
Carefully fold in roughly 1/3 of the powdered sugar mixture into the whipped egg whites. Fold a spatula into the center of the mixture, scooping down to the bottom of the bowl, and then scooping upwards along the side of the bowl. You should be making a rough circle with your spatula: center, down, out, center, down, out. Slowly but surely, your two mixtures should come together.
Once the powdered sugar mixture incorporates completely (no dryness remains), fold in the remaining powdered sugar mixture. Continue to fold the mixture until it resembles molten lava– when you pick the mixture up with your spatula, you should be able to slowly (like, slooowly) form a figure 8 without the ribbon of batter breaking.
Fit a large pastry bag with a ½ inch tip and scoop your mixture into the bag. Pipe 1¼ inch circles onto 2 parchment-lined cookie sheets, leaving at least 1¼ inches between each macaron. Allow macarons to air out for at least 1 hour, and up to 2 hours.
Preheat oven to 300°F. Bake macarons for 15 minutes. Allow to cool completely on their tray.
To finish the macarons, transfer the cooled salted caramel to a small pastry bag fitted with a 1/4 inch tip. Pipe about 1 teaspoon of salted caramel onto a macaron, then sandwich with a second macaron! Repeat until all macarons are sandwiched 🙂