Instead, the pineapple bun is so named for the crispy cookie-like shell layered on top that is thought to resemble a pineapple's skin (it's very similar to Japanese melon pan, which also tends to not contain any melon).
Pizza Hut's Pineapple Bun Stuffed Crust Pizza therefore has a crust with crispy shell and a soft, sweet crumb surrounding the standard cheese filling.
Here's a video of Pizza Hut Taiwan's Pineapple Bun Stuffed Crust in action:
