What casserole dish size should I use for this recipe? Planning to make this in a few days and am currently rounding up my supplies. Thank you!

AnneMarie - Shannon recommends the 9x13" (often used for lasagna) size. That holds about 16, and should work if the sweet potatoes are moderate size.
This chart of baking pan volumes also others that hold 16 cups (near the lasagna pan and the angel-food tube cake pan).
http://dish.allrecipes.com/cake-pan-size-conversions/
If your sweet potatoes are larger, your whole batch may need an extra small pan (layer cake or the like) or a total three of that size.

Hello! I think a 9×13-inch will do the trick. - Shannon