Preheat oven to 375 degrees. Mix sweet potatoes, milk, and melted butter and beat well. Sift and stir in the remaining ingredients. Drop by spoonfulls onto greased cookie sheet and bake 15 minutes.
Or chill 1-2 hour then turn onto a floured board, knead lightly and roll out 1/2 an inch thick. Cut with a cookie cutter. Place cookies on a greased baking sheet, and bake for 15 minutes. Sprinkle some cinnamon/sugar mixture on top.