Combine sugar, water, and corn syrup in a saucepan. Bring mixture to a boil over medium-high heat, stirring occasionally until sugar dissolves. Continue to cook, without stirring, until first sign of caramel fragrance (about 3 minutes).
Remove from heat; stir in kernel mixture. Rapidly spread mixture to about 1/8-inch thickness onto prepared baking sheet using prepared spatula. Cool completely; break into small pieces.