Lemon Macarons

Directions

1. Place the almond flour, 1-3/4 cups confectioners’ sugar and lemon zest in a food processor; pulse until thoroughly mixed to ensure almond flour is very fine. Pass almond flour mixture through a fine-mesh sieve; discard any large pieces that remain.
2. Place egg whites and salt in a very clean bowl of a stand mixer fitted with a whisk attachment; whisk on medium-low speed until frothy. Slowly add superfine sugar; whisk until dissolved, 1-2 minutes. Slowly add remaining 1/2 cup confectioners’ sugar; increase speed to high and whip until meringue is glossy and stiff peaks form, 1-2 minutes. If desired, beat in enough food coloring to achieve desired color.
3. Gently fold the almond flour mixture into meringue, a third at a time. Using the side of a spatula, smooth batter up sides of bowl several times to remove air bubbles and ensure there are no lumps; do not overmix. Run spatula down the center of the bowl; the line in the batter should remain visible for a moment before mixture runs back into itself.
4. Position rack in upper third of oven; preheat oven to 300°. Transfer batter into a pastry bag fitted with a #7 or #10 round tip. Pipe 1-3/8-in. rounds onto a parchment-lined tray about 1 in. apart. Tap tray against counter 2-3 times to remove excess air bubbles. Let macarons rest until no longer wet or sticky to the touch, 30-60 minutes. Bake, 1 tray at a time, until cookies rise about 1/8 in. to form "feet," 14-16 minutes, rotating tray halfway through baking. Remove tray and let macarons cool completely; repeat with remaining trays. Once macarons have cooled completely, remove from parchment.
5. To make filling, cream butter in a stand mixer fitted with whisk attachment; slowly add confectioners' sugar until incorporated. Add heavy cream, lemon zest and salt; mix until smooth. If desired, beat in enough food coloring to achieve desired color. Spoon frosting into a pastry bag fitted with a small round tip; pipe buttercream onto the bottoms of half the macarons. Place 1/4 tsp lemon curd in center of each frosting circle. Top with remaining macaron shells. Refrigerate, covered, until ready to serve.