Ingredients
1 c. (2 sticks) unsalted butter, room temperature
2/3 c. (130 g.) granulated sugar
1 large egg yolk
1 tbsp. lemon zest (from about 1 lemon)
1/2 tsp. kosher salt
1/2 tsp. pure vanilla extract
2 1/4 c. (270 g.) all-purpose flour
1 large egg white
2 tbsp. sanding sugar and/or nonpareils
Preparation
Step 1In the large bowl of a stand mixer fitted with the paddle attachment, beat butter and granulated sugar on medium-high speed until fluffy and paler in color, about 3 minutes. Using a flexible spatula, scrape down sides of bowl. Mix in egg yolk, lemon zest, salt, and vanilla on medium speed until combined, about 30 seconds. Mix in flour on low speed until just combined, about 30 seconds.Step 2Using spatula, scrape dough onto a sheet of plastic wrap. Pat to a disk, then tightly wrap. Refrigerate at least 2 hours or up to 2 days.Step 3Arrange racks in upper and lower thirds of oven; preheat to 300°. Line 2 baking sheets with parchment. Place another large piece of parchment on a work surface. Place unwrapped dough on parchment, then top with another large piece of parchment. Using a rolling pin, roll dough 1/4" thick. Using a 2" round cookie cutter, cut out rounds and arrange on prepared sheets, spacing 1 1/2" apart. Reroll scraps and cut out rounds from remaining dough.Step 4In a small bowl, whisk egg white until loosened and frothy, about 30 seconds. Brush tops of rounds with egg white. Sprinkle sanding sugar or sprinkles over each.Step 5Bake, rotating pans front to back and top to bottom halfway through, until cookies are firm to the touch, 25 to 30 minutes. Let cool on baking sheet 5 minutes, then transfer cookies to a wire rack and let cool completely.
What is the difference between a butter cookie and a shortbread cookie? Though they include similar ingredients, the ratio differs between butter cookies and shortbread. Contrary to what you might suspect, butter cookies have a lower amount of butter than shortbread. Butter cookies typically have eggs in the dough, while shortbread can be made with or without them. What makes a shortbread short? The word “short” in shortbread refers to the high proportion of butter in the dough. This high fat content results in a melt-in-your-mouth cookie that’s rich and crumbly. P.S. You’ll separate the egg yolk and white but won’t use the egg white for a few hours while the dough chills. Refrigerate it in an airtight container until you’re ready to use it.
