If you'd like to offer larger servings, you can certainly adapt the recipe for larger jars. Try 6-oz jars (I suggest increasing the recipe 1.5x) or 8-oz jars (I suggest increasing the recipe 2x). For the larger jars, you might prefer layering the crust and filling into four layers total (crust, filling, crust, filling) to avoid a huge layer of crust in the bottom of the jars.