This is more of a pie filling than a side dish. It is easy to prepare ahead of time and bake when you are ready. I make it for holidays a lot.
Cut a butternut squash, lengthwise, and scoop out the seeds. Place it cut side down in a pan with about an inch of water.
Peel 1-2 large sweet potatoes, cut into chunks and place in another pan.
Bake 400 deg, about 45 mins for the squash and 30 mins for the sweet potatoes.
Add 1/2 c. sugar, 1 1/2 c. milk, 1 teaspoon vanilla, 2 T flour, 2 eggs, 3 T melted butter, sprinkle of cinnamon and mix well. (I have made this and forgotten the eggs and it is fine, just not as fluffy)
Bake at 425 for 30 mins.
While it is mixing, prepare the topping
Mix about a cup of cracker crumbs (I have used graham crackers and Ritz and both are good), 1/3 c. brown sugar, and 3 T. melted butter
Add the topping and bake another 15 mins.