Sablés (French Butter Cookies)

1. Place egg in small saucepan, cover with water by 1 inch, and bring to boil over high heat. Remove pan from heat, cover, and let sit for 10 minutes. Meanwhile, fill small bowl with ice water. Using slotted spoon, transfer egg to ice water and let stand for 5 minutes. Crack egg and peel shell. Separate yolk from white; discard white. Press yolk through fine-mesh strainer into small bowl.
2. Using stand mixer fitted with paddle, beat butter, granulated sugar, salt, and cooked egg yolk on medium speed until light and fluffy, about 4 minutes, scraping down bowl as needed. Reduce speed to low, add vanilla, and mix until incorporated. Stop mixer; add flour and mix on low speed until just combined, about 30 seconds. Using rubber spatula, press dough into cohesive mass.
3. Divide dough in half. Shape each piece into log about 6 inches long and 1-3⁄4 inches in diameter. Wrap each log in parchment paper and twist ends to seal. Chill dough until firm, about 45 minutes in freezer or 2 hours in refrigerator.
4. Adjust oven racks to upper-middle and lower-middle positions and heat oven to 350 degrees. Line 2 baking sheets with parchment. Using chef’s knife, slice dough into 1⁄4-inch-thick rounds, rotating dough so that it won’t become misshapen from weight of knife. Place cookies 1 inch apart on prepared baking sheets. Using pastry brush, gently brush cookies with egg white mixture and sprinkle evenly with turbinado sugar.
5. Bake until centers of cookies are pale golden brown with edges slightly darker than centers, about 15 minutes, switching and rotating baking sheets halfway through baking. Let cookies cool on baking sheets for 5 minutes; transfer cookies to wire rack and let cool to room temperature.

CHOCOLATE SABLÉS
Reduce flour to 1-1⁄3 cups and add 1⁄4 cup Dutch-processed cocoa with flour in step 2.

LEMON SABLÉS
Add 4 teaspoons grated lemon zest with vanilla in step 2. Omit egg white mixture and turbinado sugar. Once cookies have cooled, dust with confectioners’ sugar.

TOASTED COCONUT SABLÉS
Add 1⁄3 cup finely chopped toasted sweetened coconut to dough with flour in step 2. Omit turbinado sugar. After brushing cookies with egg white mixture, sprinkle with 1⁄3 cup finely chopped untoasted sweetened coconut.

ALMOND SABLÉS
Substitute 1-1⁄2 teaspoons almond extract for vanilla extract and add 1⁄3 cup finely ground sliced almonds to dough with flour in step 2. Omit turbinado sugar. After brushing cookies with egg white mixture, gently press 3 almond slices in petal shape in center of each cookie.

CHOCOLATE SANDWICH COOKIES
In step 4, slice 1 dough log into 1⁄8-inch-thick rounds, omitting egg white mixture and turbinado sugar. Bake cookies as directed in step 5, reducing baking time to 10 to 13 minutes. Repeat with second dough log. When all cookies are completely cool, microwave 3-1⁄2 ounces chopped dark or milk chocolate at 50 percent power for 1 to 2 minutes and let cool slightly. Spread melted chocolate on bottom of 1 cookie. Place second cookie on top, slightly off-center, so some chocolate shows. Repeat with remaining melted chocolate and cookies.

VANILLA PRETZEL SABLÉS
Increase vanilla extract to 1 tablespoon and reduce chilling time in step 3 to 30 minutes (dough will not be fully hardened). Slice dough into 1⁄4-inch-thick rounds and roll into balls. Roll each ball into 6-inch rope, tapering ends. Form ropes into pretzel shapes. Proceed with recipe, brushing with egg white mixture, sprinkling with turbinado sugar, and baking as directed.