The catch to this trophy is that not every character can make every snack, and some of the higher level snacks are very rare. If you want this trophy, set everyone to snack prep as often as possible. One thing that can help speed this up is to get a Lord of the Land to level 22+. This will open up a boon that doubles the number of items you make with snack prep. I think that you need to be on a NG+ to unlock levels past 20, but the fact is that it's almost impossible to unlock this trophy on your first play without spending hours upon hours running in circles. You might as well start a new game.