Spiced chocolate sandwich cookies with miso brown butter icing

Instructions

• Make the cookies
• Add the flour to a medium-sized mixing bowl. Sift the cocoa powder on top and add in the baking powder, baking soda, salt, cinnamon, and cayenne. Stir to combine.
• In a separate bowl, using an electric mixer, beat the softened butter and granulated sugar together for a few minutes until well combined and light and fluffy. Beat in the egg white, followed by the vanilla until well-combined.
• Pour the flour mixture in batches into the butter mixture, stirring with a wooden spoon or silicone spatula just until combined. At the very end, you may need to work the dough with you hands a little bit to mix in all of the flour. Once there are no more flour patches, gather the dough into a ball, pat into a disk, and refrigerate, covered in plastic, for 15-20 minutes.
• Remove from the fridge and roll out the dough on a lightly floured surface until it is 1/8-inch thick, about the thickness of two quarters stacked on top of each other (this is thinner than you may think so take extra care to roll thinly). The dough may start to crack when you first begin rolling it out, but use your hands to gently squeeze the dough back together and keeping rolling–the cracks should disappear as you keep going.
• Use a 2-inch cookie cutter to cut out as many cookies as you can from the dough and place them on parchment-lined baking sheets. The cookies shouldn’t spread much so you can get about 25-30 on a standard baking sheet. Once you’ve finished, bunch the remaining dough together, and roll it out again to get more cookies. Repeat the process until you can’t make any more cookies. If the dough is getting too soft or sticky, you may need to briefly refrigerate it between batches. You should get around 50-60 individual cookies.
• Freeze the cookies on a baking sheet for at least 30 minutes before baking. Preheat the oven to 350F and bake for 10-14 minutes, rotating the tray and switching racks halfway through. Let cool completely before icing.
• Make the icing
• Since brown butter hardens quite a bit at room temperature, only make the icing when your cookies are ready and cooled. Flip over half of your cookies so that the bottoms are ready to be iced.
• In a small saucepan over medium heat, melt the butter. Let it continue to cook until the butter solids have turned a dark brown, swirling the pan frequently and checking the color after the loud bubbling sounds have started to subside.
• Once the butter has browned, transfer to a bowl and stir in the miso until it has dissolved into the mixture. Then add in the vanilla. Sift the confectioners sugar over the top and stir together until fully combined.
• Using a spatula, transfer the icing into a piping bag or a large gallon-size plastic bag. If using a ziplock bag, push the contents to a bottom corner and snip off the tip with a pair of scissors. Then pipe small mounds into the center of the cookies you have flipped over, about one teaspoon or a little less. Place another cookie on top and gently press down to distribute the icing in the center. Cookies can be stored in an airtight container at room temperature for one to two weeks.