Directions: |
Directions:Whisk together flour, baking powder, and salt in a small bowl.
Beat together butter and sugar in a large bowl with an electric mixer at medium-high speed until pale and fluffy, about 3 minutes in a standing mixer (preferably fitted with paddle attachment) or 6 with a handheld. Beat in egg and vanilla. Reduce speed to low, then add flour mixture and mix until just combined.
Form dough into a 12-inch log (2 inches in diameter) on a sheet of plastic wrap and roll up dough in plastic wrap. Chill dough on a baking sheet until firm, at least 4 hours.
Preheat oven to 375.
Cut enough 1/8- to 1/4-inch-thick slices from log with a heavy knife to fill 2 ungreased large baking sheets, arranging slices about 1 inch apart. If garnishing with coarse sugar, sprinkle slices with it.
Bake cookies, switching position of sheets halfway through baking, until edges are golden brown, about 12 to 15 minutes. Cool on sheets 3 minutes, then transfer with a metal spatula to wire racks to cool completely. Make more cookies with remaining dough on cooled baking sheets.
Lemon Curd
Simmer lemon juice, zest, sugar, butter, cornstarch, and salt in a 2-quart heavy saucepan over medium-high heat, whisking constantly, 1 minute. Lightly beat yolks in a small bowl, then add 1/4 cup of lemon mixture, whisking. Add yolk mixture to remaining lemon mixture, then reduce heat to low and cook, whisking constantly, until curd is thick enough to hold marks of whisk, about 2 minutes. Transfer to a bowl, then cover with plastic wrap and chill while rolling out dough. |