In baking, opposites usually attract. Sweet and salty. Cold and hot. And in the case of these cookies, mellow, sweet shortbread and tart, acidic key limes. You could use limes for this recipe, but the cookies won't really be the same. Key limes have a unique, tart flavor, with subtle yet discernible floral notes. I love limes, but to be honest, they taste a bit one-note in comparison.
Using key limes does mean that these cookies will take a little more work to prepare, given key limes' thin skin, higher seed density, and small size. In short, zesting these guys is a pain, but totally worth it.
Luckily the base cookie, which is essentially a French sable, is easy to prepare with ingredients you probably already have in your pantry (sugar, flour, butter, eggs, vanilla). The dough is one of my favorites to make ahead. Roll it into a log, cover it in plastic wrap, stick it in the freezer, then slice and bake when you're in the mood for some freshly baked cookies. Which, in this weather, is every day at 4 p.m.
- Yield:makes about 30 cookies
- Active time: 20 minutes
- Total time:1 hour 40 minutes
- 1 cup (5 ounces) all purpose flour
- 1/4 teaspoon salt
- 1 stick (8 tablespoons) unsalted butter, at room temperature
- 1/4 cup (1 2/3 ounces) sugar
- 2 tablespoons confectioners sugar
- 1 tablespoon vanilla extract
- 1 egg yolk
- 2 teaspoons zest and 1 tablespoon juice from about 4 small key limes
In a small bowl, whisk together flour and salt; set aside. In a large bowl, cream together butter, sugar, and confectioners sugar until creamy, about 3 minutes. Beat in vanilla, egg yolk, juice, and zest until combined. Add flour and salt mixture and beat just until dough comes together. Form dough into two 1 1/2-inch wide logs and wrap in plastic wrap. Let chill in refrigerator at least one hour.
Adjust oven rack to middle and upper positions and preheat oven to 350°F. Line two baking sheets with parchment paper. Slice logs into 1/4-inch coins. Bake until coins are just golden on the bottom, about 20 minutes. Let cool for 5 minutes then transfer to a wire rack to finish cooling.