If you're looking for churros in Chicago and want to go straight to the fried source, you'll end up at Don Churro, the churro factory. They're only $1, served hot, about a foot long, and you won't have to wait forever in line for them.
'desserts' on Serious Eats
Chicago is a great food city, one of my top three in the world, but it's a lousy ice cream and frozen custard 'burg. Until fairly recently you had to go to neighboring Wisconsin for standout frozen custard. But everything I tried at Scooter's, a six-year-old, seasonally open mom-and-pop frozen custard shop, was killer.