Everyone frustrated with getting their grandkids into the Museum of Ice Cream will be pleased to know this wildly imaginative popup exhibit has been extended until September 3, downtown in the former Armani store at 1 Grant Avenue. The 60-minute tour includes a tasty array of cold treats, a carousel, a mint jungle, an ice cream sandwich swing, and a sprinkle pool with 100 million custom designed sprinkles to dive into. You can’t just stroll in. You’ve got to make online reservations, then arrive 20 minutes before your assigned time. Open daily except Tuesday. $38 except for children under 2 who are free.