Prepare your workspace: Butter a large baking sheet or line it with parchment paper. Set it aside for the candy to cool.
Combine sugar, corn syrup, and water: In a large, heavy-bottomed saucepan, combine the granulated sugar, light corn syrup, and purified water. Stir over medium heat until the sugar dissolves.
Bring to a boil: Increase the heat to high and bring the mixture to a boil. Use a candy thermometer to monitor the temperature. Do not stir during this stage.
Heat to hard crack stage: Continue boiling the mixture until it reaches 300°F (150°C) on the candy thermometer (hard crack stage). This ensures that the candy will set properly.
Add cinnamon oil and coloring: Once the mixture reaches the desired temperature, remove it from heat. Carefully stir in the cinnamon candy oil and red food coloring. Be cautious, as the oil may release strong fumes.
Pour the candy: Quickly pour the hot candy mixture onto the prepared baking sheet. Tilt the sheet to spread the candy evenly. Let it cool for about 10 minutes.
Break into pieces: Once the candy has hardened, use a knife or the back of a spoon to crack it into bite-sized pieces.
Coat with powdered sugar: Place the powdered sugar in a large bowl. Toss the candy pieces in the powdered sugar to prevent them from sticking together.
Serve and enjoy: Store the candy in an airtight container at room temperature.