GRAPEFRUIT-VANILLA SHORTBREAD

Steps:

• Lightly butter pan. Pulse grapefruit zest, vanilla extract, 1/2 cup butter, and 1/3 cup powdered sugar in a food processor until smooth and homogenous. Add flour and 1/2 tsp. kosher salt; pulse just to combine. Press dough evenly into prepared pan, smoothing top with a flat-bottomed glass or measuring cup. Chill until firm, about 1 hour.
• Preheat oven to 350°F. Prick shortbread all over with a fork 1"-2" apart, and bake until edges are golden and center is pale but firm to the touch, 15-18 minutes.
• Remove band from pan and immediately cut shortbread into 16 wedges. Let cool.
• Whisk grapefruit juice, a pinch of kosher salt, and remaining 1 cup powdered sugar in a small bowl until smooth. Spread a thin layer of icing over shortbreads with a small offset spatula, leaving a thin border of crust exposed. Top as desired. Let sit 10-15 minutes to allow glaze to set. Retrace cut marks.
• Do Ahead
• Dough can be pressed into pan 1 day ahead. Cover and chill.