Lime Macarons

Instructions

• Line 2 baking sheets with parchment.

• Pass icing sugar and almond flour through a sieve into a medium bowl. Discard any coarse grinds. Set aside.

• Beat egg whites in the bowl of a stand mixer on medium, until frothy, about 30 sec. Beat in food colouring for desired colour, about 1/8 tsp. Continue beating while adding granulated sugar in a thin, steady stream. Increase speed to medium-high and beat until stiff peaks form when beaters are lifted, about 1 min.

• Fold half of almond mixture into egg whites until almost combined. Gently fold in remaining almond mixture until no streaks remain. (Mixture will look like thick cake batter.)

• Fit a piping bag with a 1/2-in. round tip. Fill bag with batter. Pipe 1- to 11/4-in.-wide rounds onto prepared sheets 1 in. apart. If piped rounds have stiff peaks, smack the bottom of the sheets on counter a few times until tops are smooth, or smooth tops using a damp finger.

• Let macarons rest in a cool place until the surface of the batter feels dry when touched, about 1 hr.

• Preheat oven to 280F.

• Bake in top and bottom thirds of oven, switching sheets halfway through, until macarons are firm and dry to the touch, 16 to 18 min. Transfer to a rack to cool completely.

• Beat icing sugar and butter in the bowl of a stand mixer on medium-low until smooth, about 1 min. Add lime juice. Increase speed to medium-high and beat until light and fluffy, 1 more min.

• Spread or pipe a heaping tsp of buttercream on half the macarons. Sandwich with remaining macarons. Macarons will keep well, stored in an airtight container at room temperature up to 2 days, or freeze up to 2 weeks.