Instructions

1. Position racks in the top and bottom thirds of the oven and preheat to 325°F. In a medium bowl, whisk together the flour, almond flour, and salt. In a large bowl, use a hand mixer to beat the butter and confectioners sugar on medium speed until pale and fluffy, 2–3 minutes. Add the egg yolk and vanilla and beat until smooth, about 1 minute. Add the flour mixture and stir with a silicone spatula until no dry patches of flour remain.
2. Transfer the dough to a lightly floured surface. Using a floured rolling pin, roll the dough ¼-inch thick. Using a 3-inch round cutter, preferably fluted, cut out rounds of dough and transfer them to two large parchment-lined baking sheets, spaced 1 inch apart. Reroll the scraps to cut out more rounds. Using a 1-inch round cutter, cut out the centers of half of the dough rounds. (Save the centers to bake separately, or reroll to cut out a few more cookies.)
3. Bake until the cookies are light golden brown at the edges and dry to the touch, 13–17 minutes, rotating and swapping the baking sheets halfway through. Transfer the baking sheets to wire racks. Set aside to cool for 1 minute, then transfer the cookies to the racks to cool completely.
4. Place a heaping teaspoon of jam in the center of each whole cookie, then spread toward the edges, leaving a border of cookie exposed. Using a fine sieve, dust the ring-shaped cookies with sugar. Place each ring-shaped cookie over a jam-coated cookie to create sandwiches, and serve.