Sweet Potato Muffins

3/4 cup canned or cooked fresh sweet potatoes, mashed
1/4 cup margarine
1/2 cup granulated sugar
1 egg
3/4 cup flour
2 teaspoons baking powder
1/2 teaspoon salt
3/4 teaspoon cinnamon
1/4 teaspoon nutmeg
1/2 cup milk
1/4 cup pecans, finely chopped
1 to 2 tablespoons cinnamon sugar

Pur