Line 3 baking sheets with waxed paper or parchment. Set aside.
In a large bowl, combine mini pretzels, toasted oat cereal, crispy corn cereal squares, salted peanuts, and candy-coated chocolate pieces. Set aside.
In a microwave-safe bowl, heat chips and oil on medium-high for 2 minutes, stirring once. Microwave on high for 10 seconds; stir until smooth. Pour over cereal mixture and mix well.
Spread onto prepared baking sheets. Cool; break apart. Store in an airtight container.