I dreamed about these cookies before I first baked them, which makes perfect sense because people who try them dream about them too. What makes these cookies so unique? Let's start with the miso--a fermented bean paste common in Japanese cooking that lends a generous dose of salty umami. Here, the miso not only adds some savory depth to a sweet cookie, but also contributes to the cookie's cakey, chewy texture. Another unique component? They're made not just with white flour, but with corn flour and crispy rice cereal dust, making for layers of mildly toasted flavor in every bite. For the grand finale, these tasty treats are glazed in a spoon-licking blend of sour cream, miso and confectioners' sugar and topped with a sprinkling of more rice cereal.
For the cookies: Blend 3 cups of the rice cereal in a blender until it turns to powder, about 25 seconds. Transfer the rice cereal powder to a small bowl and add the corn flour, salt and baking soda; mix to combine. Set aside.
Add the butter, miso paste and granulated sugar to the bowl of a stand mixer with the whisk attachment. Mix on medium-high speed for 5 full minutes, scraping down the sides with a rubber spatula halfway through. Add the egg and vanilla extract and beat on high for another 5 minutes. Reduce the mixer speed to low and slowly add the rice cereal powder-corn flour mixture. Mix until just fully combined, scraping down the sides of the bowl as needed.
Just as you did with the rice cereal mixture, slowly pour the all-purpose flour into the dough. Stir on medium-high speed for 10 seconds. Then, use the spatula to gently fold the dough into itself, making sure to fully incorporate any remaining ingredients.
Set aside two 10-by-15-inch (or similar) sheet pans. Layer each pan with a silicone baking mat or parchment paper. Form 12 balls with the dough about the size of a scoop of ice cream. Arrange 6 per sheet pan and use the back of a 1-cup measure to lightly flatten the tops of each cookie. Refrigerate for 1 hour and up to 24 hours covered with plastic wrap.
When you are ready to bake your cookies, preheat the oven to 350 degrees F.
Bake the cookies for 16 minutes on the middle rack of the oven for even coloring. You will know they are ready when they form slightly crisp, golden edges. Here's a food stylist's trick: when you remove the cookies from the oven, you can use a large round metal cookie cutter or a quart container (larger than the size of the cookies) to mold the outside edges of the cookies to give them a perfect round shape. Let the cookies cool to room temperature.
For the glaze: Combine the miso paste, 1 1/4 cups of the confectioners' sugar, 1/4 cup of the sour cream and 2 tablespoons cold water in a blender. Mix on high until you get a smooth and glossy glaze. You may need to scrape down the sides of the blender with a spatula to loosen any remaining confectioners' sugar. Pour the icing into a small bowl and mix in the remaining 1 cup confectioners' sugar with 2 tablespoons sour cream. Combine until no lumps remain. Set the glaze aside.
Now, ice and decorate the cookies. For these cookies, I recommend dividing the glaze into two small bowls and adding a few drops of festive food coloring to one bowl. Not all food dyes are created equal, so make sure to read the package instructions before adding the food dye to your glaze. Lightly drizzle the glaze across the cookies. Then, top each cookie with a sprinkle of the remaining rice cereal. Leave the iced cookies uncovered until the glaze dries, 1 to 2 hours.