Pretzel Linzers with Salted Caramel

Grind pretzels in a food processor until very powdery; you can't blend them too much. Set aside 1½ cups (155 grams) pretzel "flour"; discard remaining "flour."

Return measured amount of pretzel "flour" to food processor and add all-purpose flour, sugars, baking powder, and salt. Blend just to combine. Add butter and process until mixture is texture of cornmeal or nut flour. Add egg and continue to blend just until dough clumps.

Place a large sheet of parchment or waxed paper on a large board and drop clumpy dough on it. Use your hands to quick-mash it into one mound; don’t bother kneading dough. Place another large sheet of parchment or waxed paper on top. With a rolling pin, roll out dough into one thin (about ⅛" thick) large sheet. If sheet is too big for your counter, divide dough and roll out half at a time. Transfer board, parchment, and flattened dough to freezer and chill until dough is firm to the touch, about 15 minutes (or as long as you need to do whatever you were going to do next).

Preheat oven to 350°. Peel back first layer of parchment, use it to line a large baking sheet, and begin cutting out cookie shapes. I use a ½" and a 2" round cookie cutter, and although it would be logical to cut the 2" round first, I find that cutting interior circles first, then exterior of cookie second, allows dough to keep its shape better. You want to keep dough cold or it will be hard to lift pieces from parchment and keep them in shape; if it begins to warm up or soften, just slide dough back into freezer for a couple minutes. Reroll extra scraps. Arrange cookies 1–2" apart on prepared baking sheet.

Bake cookies until edges are golden, 10–12 minutes. Transfer pans to wire racks and let cookies cool.

Do Ahead: Sheets of dough can be made 6 months ahead; wrap well and freeze.

Meanwhile, warm cream, butter, and salt until butter melts. (I use the microwave for this.) Cook granulated sugar and syrup in a medium saucepan over medium heat until deep amber in color (305–310° on a thermometer, but you can also eyeball it). Add warmed cream mixture and stir to combine. Cook until caramel is copper in color (245–250°), then pour into a heatproof spouted cup for easy pouring. Let cool until it thickens a little, but not so much that it would be hard to pour, 25–30 minutes.

Arrange linzer lids (cookies with holes in them) in one layer and sift some powdered sugar over. Arrange bases (cookies without holes) upside down. Give caramel a stir and pour about 1 tsp. slowly, carefully, onto each base, making sure to stop about ¼" from the edges. You can always add a drop more or remove a smidge if needed. Repeat with remaining bottom cookies. Should caramel cool so much that it’s not pouring well, rewarm in microwave. Carefully lift powdered lids on top. I like to put them in the fridge just long enough so caramel can firm up, 5–10 minutes. If any lids slide out of alignment, nudge them back into place.

Do Ahead: Cookies can be made 2 weeks ahead. Store in an airtight container and chill.