These Brown Butter Oatmeal Sandwich Cookies are reminiscent of the old school, creamy icing-filled, soft, oatmeal cookie sandwich, but with an elevated twist from chai spices and brown butter! The cookie is richly caramelly, soft and chewy, and they're filled with the most incredible chai cream cheese frosting.
Begin by making the cookies. Preheat oven to 350℉. Start by making the brown butter. Melt the butter in a medium sacepan or skillet over emdium heat. Once it has melted, start whisking constantly for 3-4 minutes. Watch carefully, as it can burn easily. The butter will begin to bubble, get a little foamy, and develop a golden brown color with a nutty aroma. Once the little brown bits start to appear, keep cooking for about a minute, until the butter is golden brown, but not too dark. Remove from heat immediately and transfer to a large, heat-safe mixing bowl. Let cool completely.
Once the brown butter has cooled, add the brown sugar and granualted sugar. Whisk until smooth. Add the eggs and vanilla and whisk again until smooth and combined.
In a separate mixing bowl, whisk together the flour, quick oats, baking soda, salt, cinnamon, cardamom, nutmeg, ginger, cloves, and allspice. Add the dry ingredients to the wet, mixing with a rubber spatula until combined. Let the dough sit for 5-10 minutes before scooping.
Using a cookie scoop (I like a 1.5 tablespoon sized scoop), scoop the dough and roll into balls. Place on a parchment or silicon baking mat lined baking sheet. Bake the cookies for 10-12 minutes, or until golden brown on the edges. Let cool completely.
While cookies are cooling, make the chai cream cheese frosting. Combine the softened butter and cream cheese in a stand mixer fitted with the paddle attachment. Beat on medium speed for 2 to 3 minutes, or until mixture is light and fluffy. Reduce speed to low and gradually add the powdered sugar. Once incorporated, add the vanilla, cinnamon, cardamom, nutmeg, ginger, cloves, allspice, and salt. Beat for 30 seconds, then add the heavy cream. Increase speed to high, and beat for 1-2 minutes, or until frosting is light and fluffy. Transfer the frosting to a piping bag or plastic zip-top bag. If using a plastic bag, snip a corner of the bag off with scissors.
Lay the cookies on a cooling rack or baking sheet bottom side up, and pipe a dollop of frosting on half of the cookies, leaving a little bit of space on the borders. Top the cookie sandwiches with the remaining cookie halves. Enjoy at room temperature for 3-4 days, or keep refrigerated for 1 week.
*Extra chai cream cheese frosting will keep in the fridge for several days - you can use for more cookie sandwiches, cupcakes, or cakes!
*Raw cookie dough balls will keep in the freezer for up to 3 months!
*Cookies can be made a day or two ahead of time, and then filled with the cream cheese frosting later!