Grapefruit-Vanilla Shortbread

Preparation

1. Step 1

   Lightly butter pan. Pulse grapefruit zest, vanilla extract, ½ cup butter, and ⅓ cup powdered sugar in a food processor until smooth and homogenous. Add flour and ½ 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.

   Step 2

   Preheat oven to 350°. 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.

   Step 3

   Remove band from pan and immediately cut shortbread into 16 wedges. Let cool.

   Step 4

   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.

   Step 5

   Do Ahead: Dough can be pressed into pan 1 day ahead. Cover and chill.