Having slice-and-bake (or icebox) cookie dough in the refrigerator or freezer, ready to bake, is the ultimate sweet convenience. Essentially shortbread shaped into a log, these simple cookies have so few ingredients (just butter, sugar, salt, egg, vanilla, and flour) that imperfections are impossible to hide. With too much flour, the cookies are crisp but dry and bland; go overboard with the butter, sugar, or egg, and the cookies are rich but soft and misshapen. We set out to create a recipe for icebox cookies that would have both a crisp texture and rich buttery, vanilla flavor. First, we added as much butter as we could without the cookies losing their crisp edge; 12 tablespoons was as high as we could go. Most recipes use a whole egg, but we found that using only the yolk made the cookies firmer. We doubled the vanilla extract, but the flavor still lacked depth; replacing some of the granulated sugar with light brown sugar gave the cookies complexity. The cookies tasted great, but the texture wasn’t quite right. We had been using the traditional creaming method, a process of beating the butter and sugar to incorporate air—not ideal when the goal is a dense shortbread texture. A better option was the food processor, which combined the ingredients in seconds without whipping in much air.
- Yield: 40 Cookies
- 0.33 cup (2⅓ ounces) granulated sugar
- 2 tablespoons packed light brown sugar
- ½ teaspoon salt
- 12 tablespoons unsalted butter, cut into pieces and softened
- 1 large egg yolk
- 2 teaspoons vanilla extract
- 1½ cups (7½ ounces) all-purpose flour
- Process granulated sugar, brown sugar, and salt in food processor until no lumps of brown sugar remain, about 30 seconds. Add butter, egg yolk, and vanilla and process until smooth and creamy, about 20 seconds. Scrape down bowl, add flour, and pulse until cohesive dough forms, about 20 pulses.
- Transfer dough to lightly floured counter and roll into 10-inch log. Wrap log tightly in plastic wrap and refrigerate until firm, at least 2 hours or up to 3 days.
- Adjust oven racks to upper-middle and lower-middle positions and heat oven to 350 degrees. Line 2 baking sheets with parchment paper.
- Slice chilled dough into ¼-inch-thick rounds and space them 1 inch apart on prepared baking sheets. Bake until edges are just golden, about 15 minutes, switching and rotating sheets halfway through baking. Let cookies cool on sheets for 10 minutes, then transfer to wire rack. Repeat with remaining dough. Let cookies cool completely before serving.