One of the first places I fell in love with after moving to Chicago in the autumn of 2004 was a little place just around the corner on Broadway off Roscoe (and also down the street, by the Belmont El stop) that served the gooiest, sweetest, frostingest cinnamon rolls this side of Scandinavia: Ann Sather. This Swedish-inspired breakfast and lunch spot delivered reliably delicious offerings the many times I stopped in over the years, but the one thing I always went for was a[t least one] cinnamon roll. Hey, they come with your breakfast entrée. How can you not? On more than one occasion, I stopped by the Belmont Ave location and picked up a dozen (extra frosting please!) on my way to campus for a meeting; take note...dry research meetings are made better with gooey frosting. Always.
Also, if you're headed to Seattle from Chicago, note that Ann Sather's cinnamon rolls travel fairly well, at least within the day. Message me for my address. I'll stay up late for you.
Ann Sather's flagship restaurant is located at 909 W Belmont Ave in Chicago, Illinois, next to the Belmont El stop. They can also be found at 3145 N Broadway St and 1147 W Granville St.