Combine corn syrup, sugar, cream of tartar and water in a medium saucepan.
Cook over low heat until sugar is dissolved, stirring constantly.
Cook over high heat to 270-290°F on a candy thermometer, soft crack stage.
Add flavoring oil and food coloring if desired.
Pour into buttered shallow dish.
Let stand until almost firm.
Cut into squares.
Place candy in resealable bag with enough confectioners sugar to coat pieces. Shake bag. The dusting of sugar
prevents the candy pieces from sticking to each other.
Makes about 3 1/4 pounds. Good for Christmas gifts.