Coat a 9-inch square baking dish with cooking spray. Gently stir together cereal, potato chips, macadamia nuts, and 1 cup white baking chips in a large bowl.
Melt butter in a large saucepan over medium. Add marshmallows; cook, stirring constantly, until melted and smooth, about 2 minutes. Remove from heat and stir in vanilla. Immediately pour over cereal mixture and gently stir until thoroughly combined. Transfer mixture to prepared baking dish and smooth top.
Place remaining ⅓ cup white baking chips in a small microwaveable bowl. Microwave chips on medium (50 percent) power in 30-second intervals, stirring after each interval, until melted and smooth, 1 to 1 ½ minutes total. Let stand until completely cool and set, about 1 hour. Store bars in an airtight container at room temperature for up to 3 days.