Heat oven to 200°F. Coat 15 x 10 x 1-inch baking pan with no-stick cooking spray. Place popcorn in large bowl. Discard any unpopped kernels.
Remove lid from topping. Microwave on HIGH 30 seconds to warm.
Drizzle topping over popcorn, stirring to coat evenly. Spread evenly in prepared pan. Bake 40 minutes, stirring halfway through cooking time. Stir in cashews. Sprinkle evenly with salt. Bake an additional 15 minutes. Cool completely on sheets of wax paper. Store in airtight container.