1. Preheat oven to 325 degrees. Pulse flour, sugar, and salt in a food processor until combined. Add butter, and pulse until the mixture resembles coarse crumbs. With machine running, pour in 1/4 cup cream and the vanilla, and process until dough just comes together.

2. Roll dough between lightly floured sheets of parchment until 1/16 inch thick. Using a 2 1/2-inch fluted cutter, cut out 36 rounds, gathering together scraps and rerolling if needed. Space 1 inch apart on parchment-lined baking sheets. Chill in freezer until firm, about 15 minutes.

3. Whisk together egg yolk and remaining tablespoon cream. Brush onto tops of cookies. Bake until golden brown, 15 to 20 minutes. Let cool. (Unfilled cookies can be stored in an airtight container up to 4 days.)

4. Turn over half the cookies, and spread 1 heaping teaspoon chocolate or chocolate-hazelnut spread onto each. Top with remaining cookies. Refrigerate until set, about 15 minutes (or up to 2 days; cookies will soften slightly with longer storage).