My Sweet Potato Casserole

If you don't like sweet potatoes, you will LOVE this anyway. I read over a few recipes and came up with my own version that has less fat and less sugar. It was great.

3cups sweet potatoes, cooked and mashed (about 3 big potatoes)
1/2 cup sugar
1/2 stick butter
1 egg
1/2 cup milk
1 T vanilla
Topping:
1/3 cup butter
1/3 cup flour
1 cup brown sugar
1 cup chopped pecans (or walnuts if you don't have/like pecans)

Mix the first set of ingredients together until well incorporated, then spread in a large baking dish (9*12). Mix the topping up in a bowl (with your fingers) and top the potatoes.
Bake 35-40minutes at 350 degrees.