Maybe slice and parboil the sweet potatoes first, and then refrigerate? Slice apples the day of, then assemble and bake.

OP here. Mushiness, and the apples getting messed up if I don’t bake it right away. Guess I will wait until day of to prep it. Thanks, all.

13:24 here: thank you! I won’t make this for THX but will definitely try it soon!

Not OP, but a basic recipe: https://www.allrecipes.com/recipe/22150/yam-and-apple-casserole/

What are you worried about, mushiness?

Sounds like a lovely dish - can you point me to a recipe for a 1st timer?

I think you could half bake on Wednesday and finish on Thursday but I agree with PP that the sugars will start to break down and it will get mushy.

I brought this dish to my work potluck. Baked it the night before, refrigerated, and then reheated over sterno day-of. It was mushy. Fine for a work party, but I would have been disappointed for Thanksgiving.

Sounds delicious. I would toss the apples with lemon juice or citric acid (like Fruit Fresh) to keep them from getting too brown. With that, I think it'd be fine.

Have a standard Thanksgiving dish in my family that is sliced sweet potatoes that I parboil a bit, layered with sliced apples, with a mix of brown sugar, orange, spices butter, etc poured over. Baked for a good hour or more.
I would love to prep it on Wednesday. Do you think I could? I’m worried mostly about the apples. Thanks.