SPRAY a large bowl with cooking spray. Add popcorn, peanuts and pretzels.
COOK corn syrup and butter in a medium saucepan over medium heat. Stirring constantly, bring to a full boil for 1 minute. Remove from heat and add butterscotch chips, stirring until melted. Pour over popcorn mixture and mix well. Stir in candy coated chocolate pieces.
Press into a greased 13 x 9-inch pan. Cool at least one hour. Cut into bars.