Pierce the apples with the treat sticks in the center where the stem inserts into the apples and run the stick 3/4 of the way through the apples. Bring a pot of water to boil. Dip each apple in the boiling water for 10 seconds before patting dry with a clean towel. Once all apples have been dried, use a new dry cloth to dry the outside again. Set apples aside. Lay out a piece of parchment paper on a clean and even work surface next to the apples. Spray parchment with cooking spray, not letting any of the cooking spray get on the apples.

In a tall medium-sized saucepan, whisk together sugar, water, corn syrup, and red food coloring until food coloring is evenly distributed. Place over medium-high heat and do not stir as you bring to a boil. Boil until sugar mixture reaches 300°F on a candy thermometer, 20 to 25 minutes. (Note: it is critical that you do not stir this sugar mixture.)

Immediately remove mixture from heat and carry pan to the apples and parchment paper. Tilt saucepan so the liquid sugar is all on one side of the pan. Use your other hand to dip an apple in the candy, twirling the apple to evenly coat the outside. Lift apple out of sugar, allowing excess to drip off, and place the coated apple on the greased parchment paper with the stick pointing up. Working quickly, repeat dipping process with remaining apples. Allow candy to cool and harden completely before serving, about 15 minutes.