A Peach Tart can be made by Zess T. in Paper Mario: The Thousand-Year Door. It's created by cooking a Peachy Peach with Cake Mix. In battle, the item will randomly give the user a Dodgy, Electrified, or Sleepy status.
The same recipe works in Super Paper Mario. Here, a Peach Tart restores 15 HP and cures poison. You give the same ingredients to Dyllis to make it.