Add oil to a large pan and add one or two kernels of popcorn. Cover and place over medium-high heat. When kernels have popped add the remaining kernels.

Cover with the lid. Shake the pan occasionally and continue to cook until popping slows to 2 seconds between pops.

Remove from heat and pour over cooling racks to remove unpopped kernels. Place popcorn in a large bowl and set aside.

Preheat oven to 250°.

Make the caramel sauce by adding butter, brown sugar and corn syrup in a heavy saucepan and place over medium high heat.

Stir until butter is melted and bring to a boil. Cook at a rolling boil for 5 minutes without stirring.

Set off of heat and stir in baking soda, salt and vanilla.

Pour over popcorn and stir until well combined.

Spread onto 2 rimmed baking sheets in an even layer.

Bake for 45 minutes, turning popcorn and stirring every 15 minutes.

Allow caramel corn to cool completely and store in airtight containers.