Ingredients
3/4 cup cake flour, (not self-rising)
1/2 cup all-purpose flour, plus more for work surface
1/2 teaspoon salt
1 teaspoon baking powder
10 tablespoons unsalted butter
1/4 cup sugar
Grated zest of 1 lemon
1/2 teaspoon pure vanilla extract
1 large whole egg
1 large egg yolk
Preparation
Sift together flours, salt, and baking powder into a medium bowl, and set aside. In the bowl of anelectric mixer fitted with the paddle attachment,cream the butter, sugar, lemon zest, and vanilla on medium speed until mixture is light and fluffy.
Add the eggs and yolk, one at a time, beating until well incorporated after each addition. Add flour mixture, and beat on low speed until just combined. Turn out onto plastic wrap; pat into a square about1 inch thick. Wrap well in plastic; refrigerate until firm, at least 2 hours.
Turn out dough onto a lightly floured work surface; roll out to 1/4 inch thick. Cut into 2-inch squares with a paring knife, transfer squares to a parchment-linedbaking sheet. Cover with plastic wrap; refrigerate until firm, at least 30 minutes.
