Push a wooden craft stick into the top of each apple. Bring sugar, corn syrup, and water to a boil in a medium, heavy saucepan, stirring until sugar dissolves. Bring to a boil over medium-high heat. Cook, without stirring, 9 minutes or until lightly golden (about 260°). Stir half-and-half, vanilla, and salt into caramel mixture. Simmer until candy thermometer registers 235°, stirring frequently. Stir in pumpkin pie spice. Pour caramel into a bowl sitting in a hot water bath.
Place graham cracker crumbs in a bowl.
Combine white chocolate chips and canola oil in a microwave-safe bowl. Microwave at HIGH until melted, stirring every 20 seconds.
Swirl bottom halves of apples in caramel; dip in crumbs. Drizzle with white chocolate.
