If you thought Pizza Hut was done innovating new ways to experiment with pizza crust, you were mistaken. Starting today, the chain will roll out its cheesiest creation yet: Mozzarella Poppers Pizza.

In the movie Mystic Pizza, Jojo, the character played by Lili Taylor, asks Julia Roberts’s Daisy, “What the hell do you think Leona really puts in that pizza?” The answer for most pizza chains is ...