1. Preheat oven to 300 degrees F.
2. Line a large, rimmed baking pan (17x 12 –inches) with foil and spray lightly with cooking spray.
3. Spray a large mixing bowl (not plastic) with cooking spray and add popcorn (make sure to remove unpopped kernels) and nuts; set aside.
4. In a medium saucepan, combine chocolate morsels, corn syrup and butter. Cook over medium heat, stirring constantly, until mixture boils. Pour over popcorn; toss well to coat.
5. Spread in an even layer into prepared baking pan. Bake in preheated oven 40 minutes, stirring every 10 minutes.
6. Cool completely in pan. Break into pieces; store in an airtight container.

Note: Clean-up tip: Soak saucepan before cleaning.