Portillo’s, the fast-casual restaurant concept known for its menu of Chicago-style street food, and iconic bakery chain Milk Bar have teamed up to create a limited-edition treat – the Portillo’s Chocolate Cake Cookie.

This rich and fudgy soft baked cookie combines the flavors of Portillo’s moist chocolate cake with swirls, pops and chunks of Portillo’s fudge frosting, all baked into a Milk Bar chocolate cookie.

“Portillo’s world-famous, homemade chocolate cake is iconic,” says Garrett Kern, Portillo’s vice president of strategy and culinary. “This delicious dessert has been a staple on our menu for decades, and when we were given the chance to collaborate with the fantastic Christina Tosi and Milk Bar, we knew we had the ultimate opportunity to transform our fan-favorite cake into hand-held treats Portillo’s, Milk Bar and chocolate lovers everywhere could enjoy.”

Starting Tuesday, October 8, the limited-edition, individually-wrapped Portillo’s Chocolate Cake Cookie will be available for purchase inside at all Portillo’s restaurants with dining rooms via the grab-and-go display. In addition, a six-count Cookie Tin will be available for nationwide shipping on Milk Bar’s website, while supplies last.

“Famous for VERY good reason, there is perhaps no greater restaurant dessert idol than Portillo's Chocolate Cake- plump, rich, soft, understated yet an absolute home run. A celebration any and every day of the week. Both the chef and the home baker in me look to this perfect specimen whenever I get into the kitchen to create something that will move people, start legendary rumors, stand the test of time,” says Christina Tosi, Milk Bar founder. “It is one of the coolest moments of our careers to bake a love letter to this icon through the lens of a Milk Bar Cookie- dense and fudgy, yet flirtatiously cakey with pops of chocolate frosting drops.”