Peanut Butter & Jelly Cookie Sandos

Gather the ingredients.

Line 2 baking sheets with parchment paper and preheat the oven to 350 F.

Whisk together the flour, baking soda, baking powder, and salt in a medium bowl. Set aside.

Cream together the butter, brown and granulated sugars, miso, peanut butter, and vanilla in a stand mixer fitted with the paddle attachment on medium speed until lightened in color and fluffy, about 5 minutes. Scrape down the sides of the bowl as needed.

Whisk 2 of the egg whites in a small bowl until foamy, then add to the ingredients in the stand mixer, mixing just until combined.

Add the dry ingredients in 3 increments, mixing on medium-low speed after each addition, until combined. Cover the bowl with plastic wrap and refrigerate for 1 hour.

Dump the dough onto a lightly floured surface and knead briefly to bring it together in a cohesive mass. Roll the dough out until it is about 1/4-inch thick.

Cut out the cookies with whatever shape cutter you like (we used a 2-inch round cutter) and transfer to the prepared baking sheets. You can re-roll the dough and cut as many times as you need. You should have about 60 total cookies depending on the size of your cutter.

Brush the top of each cookie lightly with the remaining egg white, then sprinkle with sesame seeds.

Bake until golden brown around the edges, rotating and switching the position of the trays halfway through, 8 to 10 minutes. Let cool completely on the sheet pans on racks.

While the cookies bake, prepare the filling. Beat the softened butter in the bowl of the stand mixer fitted with a paddle attachment until it is light in texture. Add the confectioners' sugar and mix on low until almost combined.

Add the milk and jam, then continue to beat the mixture until fluffy and aerated.

Once the cookies are cooled, either pipe or spread the frosting on the bottom-side of half of the cookies, then sandwich with the remaining halves.