Ok, here's MY Version of this dish... just remember I don't know how to measure, but below is starter measurements that I use and of course being trained by my grandma well I don't stick to "original recipes" usually - I doctor them for my own taste as most do.
3 cups cooked, mashed sweet potatoes
1 cup of regular sugar
2 beaten eggs
1 teaspoon vanilla extract
1/3 cup milk
1/2 cup Butter(I use REAL butter, not Margarine or spreads)
1/2 to 1 cup Brown Sugar(start with 1/2 cup - taste, add extra until you reached desired sweetness you want, I don't use no more than 1 cup of this as it cooks the sugars melt and blend to make it sweeter than you tasted originally)
*some will add 1/2 tsp. of cinnamon to this -I prefer not to and its just fine*
~I usually end up with a casserole dish thats about 1 1/2" deep - and 18"L x 9"W - I end up doubling my recipe before its over so I've enough for more than one meal. Doubling makes a fairly decent amount and will be good in fridge for about 5 or 6 days. Whatever meat I serve with it, hubby will generally eat it over and over using the sweet potatoes as a "topping". He enjoys this enough to eat it cold, but I say yuck! LOL
First off, boil your sweet potatoes with skin on - I usually use about 6 to 8 large sweet potatoes. Boil until you can fork them all the way through with ease. Once they are done remove from water, let cool until you are able to handle them, they will be extremely hot for a while. Once they cool I found the best way to peel them is to take a really sharp knife and go down the skin lengthwise, bout 1/8th inch into the potatoe. This should remove the outer skin and "shell" as you'll notice on the potatoe after you cut it. The "shell" part is darker than the rest of the potatoe so you'll want to get rid of that too, it usually is what is holding the little stems around the potatoe. Once all are peeled - put in a large bowl or mixer and mash the dickens out of them as if you were making mashed potatoes.
Add the other ingredients listed above and bake at 375 degrees for 45 minutes then check it. When you check it - it should be "set" almost like a cake. Don't go poking toothpicks in it or knives because they ain't gonna come out clean, but you'll notice a difference when baking it how the top will form a skin of sorts, thats what you want! Once ya get that far, move on to next step - the topping.
Here again a matter of preference, but my family doesn't like Marshmallow GOO! Especially on their sweet potatoes. My husband HATES any form of nuts therefore to get a "crunch" topping here's what I do.
Get out the brown sugar again, take and crumble it all over the top of the casserole until you've covered it completely. Yes, you may still see some areas of orange in there and that's fine, Amount of topping is totally up to you! Once I've covered the top I turn the oven on Broil and let it come up to temperature. Place the casserole dish in the oven and DO NOT leave - watch it until it turns a Dark golden brown, DO NOT burn the sugar or you'll end up with YUCKY taters, lol.
Once this is done, take from oven, let cool, eat and enjoy!