Step 1

Heat oil in a large pot over medium heat. Add a few pieces of popcorn and wait until it pops, then quickly remove.

Step 2

Add remaining popcorn, elevate off stove to shake and spread corn out evenly. Cover with a lid. Once the popcorn starts popping in earnest, shake the pot gently once.

Step 3

Remove from heat when the popping stops (when you can count to 3 between pops) and transfer to a (very!) large bowl. You need 10 cups of popcorn.

Step 4

Preheat oven to 110°C/230°F.

Step 5

Melt butter in a saucepaan over medium heat.

Step 6

Add sugar, corn syrup and salt. Stir until just combined.

Step 7

When it starts to bubble, simmer for 4 minutes - DO NOT STIR!

Step 8

Remove from heat then quickly whisk in vanilla and baking soda. When you stop whisking, the caramel will foam and increase in volume.

Step 9

Quickly pour straight over popcorn, toss until caramel cools and starts to harden.

Step 10

Spread popcorn on 2 baking trays.

Step 11

Bake for 45 minutes, tossing every 10 minutes or so. Caramel will remelt for the first 2-3 tosses - tossing coats popcorn more evenly with caramel. (If using glucose, bake further 15 minutes).

Step 12

Remove from oven, leave to cool. Gently break into pieces and serve. Stays crisp 2 - 3 weeks!