Thanksgiving side: sweet potato casserole!

There's one thing I can't have Thanksgiving without, and that's my family's sweet potato casserole.  You can tell I've made it a lot just by looking  the page in the cookbook it's on:

This is from "Heritage of Hospitality" which is a Junior League of Winston-Salem Cookbook from 1975.  I think it might be the first cookbook I ever owned.  My mom was one of the editors, and I remember her testing recipes and also piles and piles of these bright yellow cookbooks with green binding all over our house.  The sweet potato casserole is one of two recipes she had in the cookbook - another is for a grilled leg of lamb that I still use. Somewhere I think I have the original recipe card that my grandmama wrote it down on.   I've modified her recipe a bit, and I always rant at Thanksgiving that I never know how much "6 or 7" sweet potatoes are.  Especially when this is what I've got to work with:

I think it ended up being about 6 lbs, but that seems like too much. You need enough mashed sweet potato to fill a 9"x13" casserole dish.  I also bake the sweet potatoes rather than boil them.

Here's the recipe typed out:
Sweet potato casserole
Casserole filling:
6 or 7 sweet potatoes
1/2 stick butter (4 tbs)
2 eggs
1/2 cup brown sugar
1/4 cup half and half
cinnamon, nutmeg and vanilla to taste (I usually add about 1/4-1/2 tsp cinnamon, 1/4 tsp nutmeg and 1/2 tsp vanilla - I think I forgot the vanilla this year).  I also added some salt  - maybe about 1/4 tsp?

Topping:
1 cup crushed cornflakes
1/2 cup brown sugar
1/4 cup chopped pecans
1/2 stick butter, melted

Directions:
 Preaheat oven to 350 and spray casserole with non-stick spray.

Wash sweet potatoes well, prick all over with fork to let steam escape and place on baking sheet.  Bake at 350°F until tender (fork slides in easily), about 1 hour.  Let cool enough to handle and peel.  Place warm potatoes in mixer and stir with paddle attachment to mash (you could also mash by hand).  Add butter, eggs (I usually beat the eggs a bit before I add them), brown sugar and half and half.  Mix well.   Season to taste and spread potato mixture in casserole.  You can cover at this point and refrigerate overnight.

When you're ready to bake the casserole, mix together the dry topping ingredients and then add the butter. Spread evenly over the top of the potato mixture.  If the casserole is warm, bake in a 450 oven for 15 minutes until heated through and the topping is browned.  If baking from the refrigerator, I usually turn the oven down to 350 and let it bake until heated through and the topping is browned, maybe 20-30 min?  Keep an eye on it.  Sorry this is vague but you're usually heating this up while you're waiting for the turkey to rest and finishing up all the other bits and pieces of Thanksgiving dinner so the goal is just to get it hot and not burn it.  It's pretty forgiving.  I'm much more likely to burn the rolls than this!

The potatoes going into the oven:

The finished product:

We have finally grown into the amount of food we make at Thanksgiving, thanks to these guys:

Edited to add in 2021 I used 7.5 lbs sweet potatoes and filled the casserole above (13x9 pyrex) and a 9x9 square casserole as well (maybe not as generously but I think a thinner layer is good).  So I think 6 lbs for the 13x9 would do, and 2-3 lbs for a 9x9.