Put the sugar, water, and corn syrup in a
saucepan and heat until the
sugar is dissolved, stirring occasionally. Carefully, transfer the mixture to a container and cool in the refrigerator without a lid, or place the container in an ice bath.
Without peeling, cut the apple away from the
core. Cut the apples into a large
dice and toss with 1 tablespoon fresh
lemon juice.
Add the apples and cooled syrup to a
blender and puree until smooth.
Strain the mixture and add the remaining 1 tablespoon lemon juice right away. Refrigerate, about 1 hour. Remove from the refrigerator and pour into the bowl of an ice cream machine. Freeze according to the manufacturer's instructions.