Pour the Chex Cereal and half the chocolate candy in a large bowl.
In a microwave-safe bowl, combine the peanut butter, white chocolate chips, butter, and olive oil. Microwave on high for 30 seconds. Stir and microwave again in 15-second intervals until melted and smooth (mine took about a minute). Then mix in the vanilla extract.
Pour the melted peanut butter mixture over the cereal and quickly stir to coat. Slowly pour the powdered sugar into the bowl and gently mix until everything is coated in sugar. Pour the mixture onto a baking sheet to cool.
Transfer the puppy chow into a serving bowl and add the remaining chocolate candy. Stir to combine. Serve or store in an airtight container for up to a week!