Sables (French butter cookies) were Kevin Sbraga's favorites growing up. "I'd sneak them when I wasn't supposed to," he says. His wife, Jesmary, who teaches baking, had the idea to sandwich them with lemon curd.
In a standing electric mixer, beat the butter with the sugar at medium speed until creamy. Add the egg yolks and vanilla bean seeds and beat until smooth.
In a food processor, combine the almonds with the salt, baking powder and flour and process until the almonds are finely ground. Add the dry ingredients to the mixing bowl and beat on low speed until smooth. Pat the dough into 2 disks, wrap in plastic and refrigerate until chilled, about 1 hour.
Preheat the oven to 350° and line 2 baking sheets with parchment paper. Working in batches if necessary, roll out the dough 1/4 inch thick on a lightly floured surface. Using a 1 3/4-inch round cutter, stamp out cookies as close together as possible. Arrange the cookies 1 inch apart on the prepared baking sheets. Bake the cookies in the upper and middle thirds of the oven for about 22 minutes or until lightly browned on the bottom and around the edges. Let cool on the baking sheet, then transfer to a platter. Meanwhile, refrigerate the scraps until chilled, then reroll, stamp out more cookies and bake.
Top half of the cookies with a rounded teaspoon of the Tangy Lemon Curd. Refrigerate until the curd is set, about 15 minutes. Top with the remaining cookies. Refrigerate for 8 hours before serving.
The unfilled cookies can be refrigerated for up to 1 month. Sandwiched cookies can be refrigerated overnight.