The Circa '21 Dinner Playhouse's current family musical, Pinkalicious, is as lightweight and sweet as cotton candy, and about as nourishing; it gives you a friendly sugar rush and all but evaporates on contact. Yet hidden within the show's pleasant, amiable presentation are moments of delightfully loopy comic invention, and throwaway bits so surprising and bubbly and odd that the production lingers in your head far longer than you'd expect it to. It's cotton candy, all right, but it's cotton candy filled with Pop Rocks.