1. Remove and discard all unpopped kernels from popcorn. In 15 x 10 x 2-inch baking pan coated with cooking spray combine popcorn, KELLOGG’S CORN FLAKES cereal and nuts.
2. In medium saucepan combine brown sugar, butter and corn syrup. Cook and stir over medium heat until boiling rapidly. Boil for 5 minutes, stirring constantly. Remove from heat.
3. Pour caramel mixture over popcorn mixture. Stir gently until coated. Bake at 300°F for 15 minutes. Stir. Bake at 300°F for 5 minutes more. Remove from oven. Spread on foil coated with cooking spray. Immediately, sprinkle with toffee pieces and butterscotch morsels. Cool completely. Break mixture into clumps. Store in airtight container for up to 1 week.