Pb&J Sandwich Cookies Recipe

Combine butter, peanut butter, sugar, baking soda, and salt in the bowl of a stand mixer fitted with a paddle attachment. Cream on medium speed until soft, about 5 minutes, then add egg whites in 4 or 5 additions. After incorporating, scrape bowl and beater with a flexible spatula; resume mixing on low and sprinkle in flour to form a soft dough. Divide in half and flatten into disks. If dough is too soft to roll, wrap in plastic and refrigerate until firm, about 30 minutes.
Adjust oven rack to middle position and preheat to 350u0b0F. On a generously floured surface, roll a portion of dough into a 5-inch square. Sprinkle with more flour, flip onto the other side, then dust again and roll until about 1/8 inch thick. If necessary, loosen dough from work surface with an offset spatula, then cut into 2-inch rounds, or whatever shape you prefer. Use spatula to transfer to a parchment-lined half sheet pan, then gather scraps, re-roll, and cut again. Repeat with remaining dough. Bake cookies until pale gold around the very edges, about 12 minutes. Cool completely and store in an airtight container until ready to serve.
Spread a tablespoon of peanut butter over the bottom of half the cookies, top with a teaspoon of jam or jelly, then sandwich with remaining cookies. Serve immediately or store in an airtight container up to 24 hours.