Line a 15-in. x 10-in. x 1-in. pan with foil; butter the foil and set aside. In a large heavy saucepan, combine water, sugar, corn syrup and food coloring. Bring to a boil over medium heat, stirring occasionally. Cover and cook for 3 minutes to dissolve sugar crystals.
• Uncover; cook on medium-high heat, without stirring, until a candy thermometer reads 300° (hard-crack stage), about 25 minutes. Remove from the heat; stir in cinnamon oil (keep face away from mixture as oil is very strong). Immediately pour onto prepared pan. Cool completely, about 45 minutes.
• Break the candy into pieces using the edge of a metal mallet. Sprinkle both sides of candy with confectioners' sugar. Store in airtight container. Yield: about 2 pounds.
Editor's Note: Cinnamon oil can be found in some pharmacies or at kitchen and cake decorating supply stores.
We recommend that you test your candy thermometer before each use by bringing water to a boil; the thermometer should read 212°. Adjust your recipe temperature up or down based on your test.