Southern Candied Sweet Potatoes

6 lge sweet potatoes
1/2 cup butter or margarine
2 cups white sugar
1 tsp ground cinnamon
1 tsp ground nutmeg
1 tbsp vanilla extract
dash salt

Peel the potatoes & cut them into slices. melt the butter or margarine in a skillet & add the sliced potatoes. Mix the sugar, cinnamon, nutmeg & salt. Cover skillet; reduce heat to low & cook for about 1 hour or until potatoes are "candied". They should be tender but a little hard around the edges. Also, the sauce will turn dark. You will need to stir occasionally during cooking. Stir in the vanilla just before serving.