Cool completely. Wrap individually in plastic wrap.
Step 2
Preheat the oven to 300 degrees F (150 degrees C). Coat a large roasting pan with cooking spray.
Step 3
Add popcorn to the prepared roasting pan; place in oven until warm. (Popcorn can also be warmed in a large microwave-safe bowl on High (100%) power for 1 to 2 minutes.)
Step 4
Combine sugar, corn syrup, butter, and salt in a heavy 2-quart saucepan; bring to boil over medium heat, stirring constantly. Boil 2 minutes, continuing to stir.
Step 5
Off heat, stir in vanilla and baking soda; pour over warm popcorn, stirring until well coated. Cover hands with two plastic bags, coat bags lightly with cooking spray; shape mixture into twelve 3-inch popcorn balls, working quickly.