Preheat oven to 250°F. Spray two large baking sheets with cooking spray and divide popcorn evenly between them.
In a large saucepan, combine brown sugar, corn syrup, margarine, and salt over medium heat. Stir constantly until butter and sugar melt and mixture begins to boil, about 5 minutes.
Boil for 5 minutes, stirring constantly. Remove from heat and quickly stir in vanilla and baking soda.
Immediately pour half the caramel over the popcorn on each baking sheet. Stir quickly to coat as much as possible (it’s fine if not fully coated yet).
Bake for 1 hour, stirring every 15 minutes to evenly coat.
While baking, prepare two more baking sheets with parchment paper.
Transfer baked caramel corn to the parchment-lined sheets to cool. Break up clumps before serving.
Notes
🥡 STORAGE
Store in an airtight container at room temperature for up to 2 weeks.
♨️ REHEATING
No reheating needed, but if you prefer it warm, bake at 250°F for 5-10 minutes.
❄️ FREEZING
Freeze in airtight containers or freezer bags for up to 6 months. Thaw at room temperature before serving.
💡 TIPS FOR BEST RESULTS
Work quickly when coating the popcorn to prevent the caramel from hardening too soon.
Stirring during baking helps the caramel coat evenly.
Use a heatproof spatula for stirring to avoid sticking.
🍳 ALTERNATE COOKING METHODS
Stovetop: After coating, let caramel corn cool on parchment instead of baking for a softer texture (less crunchy).
♻️ LEFTOVERS
Enjoy as a snack, crumble over ice cream, or package in bags for gifts.