PETIT BEURRE COOKIES OR CRUMBS

Steps:

• For the Dough
• Cut the 1/2 pound butter into pieces and put it in the bowl of a standing mixer fitted with the paddle. Beat until light. Add the flour, confectioners' sugar, almond flour, and vanilla extract. Mix until the dough comes together. Turn the dough out onto a lightly floured counter and divide it in half. Form each half into a brick and wrap in plastic. Refrigerate one packet for at least 1 hour and freeze the other for up to 3 months.
• Heat the oven to 350°F or 325°F on convection.
• Remove the dough from the refrigerator and roll it between two sheets of parchment to 1/8 inch thick. Lift it up onto a baking sheet, peel off the top parchment, and clean up the edges. Bake until golden, 19 to 21 minutes, rotating the pan halfway through baking. Let cool completely.
• Crumble the cookie and put it back in the clean bowl of a standing mixer fitted with the paddle. Mix for a minute or so to make smaller crumbs. Add the 3 tablespoons butter and mix. If the dough doesn't come together, add 1 or 2 tablespoons butter, a tablespoon at a time, mixing until you have a dough you can roll.
• Roll the dough between two pieces of parchment to 1/4 inch thick. Freeze for 1 hour.
• If you're making crumbs, carefully peel off the top piece of parchment. Bake until golden, about 15 minutes, rotating the pan halfway through baking. Let cool, then crumble and store in an airtight container for up to 2 days.
• For Cookies
• If you're making cookies, carefully peel off the top piece of parchment. Cut the frozen dough with a 1 1/2-inch cutter. The cookies will be too delicate to move, so instead remove the excess dough from the parchment. Slide the parchment onto a baking sheet.
• Beat the egg and yolk together until smooth. Brush onto the cookies. Mix the salt and sugar together and sprinkle over the cookies.
• Bake until a rich golden brown, about 15 minutes, rotating the pan halfway through baking. Let cool. The cookies will be very delicate, so don't move them around. Leave them on the pan until you serve them.