01 -  Line a large baking sheet with parchment paper and lightly grease. Insert a wooden stick into the stem end of each apple, pushing halfway through. 
 02 -  Combine granulated sugar, water, light corn syrup, and cream of tartar (if using) in a medium, heavy-bottomed saucepan. Stir gently until integrated. 
 03 -  Set the saucepan over medium heat and cook the mixture without stirring until it reaches 300°F on a candy thermometer (hard crack stage). Swirl the pan gently if needed to distribute heat. 
 04 -  Remove the saucepan from heat when at temperature. Swiftly stir in vanilla extract and black gel food coloring until evenly mixed. 
 05 -  Working quickly with caution, tilt the pan and dip each apple into the hot syrup, swirling to fully coat. Allow extra candy mixture to drip off before setting each apple on the prepared baking sheet. 
 06 -  Let apples cool at room temperature until the candy shell hardens, approximately 15–20 minutes.