Line a large baking sheet with foil; set aside. In a microwave-safe bowl, combine vanilla-flavor candy coating and white chocolate baking squares. Microwave, uncovered, on 100-percent power (high) for 2 to 3 minutes, stirring once halfway through cooking time. Stir until smooth. Pour onto prepared baking sheet and spread into a 10x8-inch rectangle; set aside.
In another microwave-safe bowl, combine chocolate-flavor candy coating and milk chocolate bar. Microwave, uncovered, on 100- percent power (high) for 2 to 3 minutes, stirring once halfway through cooking time. Stir until smooth.
Slowly pour chocolate mixture over white mixture on baking sheet. Use a thin spatula to swirl chocolate mixture into white mixture. Shake baking sheet gently for even thickness.
Sprinkle with crushed candy canes. Chill about 30 minutes or until firm. Use foil to lift candy from baking sheet; break candy into pieces. Arrange candy in jar; cover.