This is the one I use, it's out of the Southern Sideboards cookbook.
Sweet Potato Custard Pie-----My husband say if you eat it warm it's considered a veggie, lol
1 small sweet potato peeled, boiled and mashed with 1/2 cup butter.
Beat in 1 1/2 cups of sugar, 1 TBSp sifted flour, 1 tsp each vanilla and lemon extract.
Add 3 eggs, one at a time, mixing well after each.
Beat in 1 5-ounce can of evaporated milk.
Pour filling into a 9 inch deep dish pie shell
Bake at 350* for 45 minutes or until set.
I top it with marshmallow cream or mini mashmallow and slide it back in the oven for about 5minutes to brown.
ETA---I have also poured it into individual rammakins as a side dish