Preheat oven to 350 degrees Fahrenheit.

In a large bowl, combine 1 cup of sugar (1/2 brown and 1/2 white), 2 cups of cooked, peeled, and mashed sweet potatoes, and 3 cups of milk.

Beat 4 eggs and add them to the sweet potato mixture.

Add 1/2 tsp. of salt and 2 tsp. of cinnamon to the mixture.

Stir all ingredients together until well combined.

Pour the mixture into one large unbaked pie shell or two smaller ones.

Bake for approximately 1 hour, or until the filling is set and the crust is golden brown.