1Step 1: Pop the popcorn
Heat avocado oil in a large pot over medium-high heat. Add popcorn kernels, cover, and shake occasionally until popping slows. Remove from heat. Discard any unpopped kernels and transfer popcorn to a large mixing bowl.
2Step 2: Toast the pecans
Spread pecans on a baking sheet and toast at 350°F for 6–8 minutes, or until fragrant and golden. Let cool slightly, then chop.
3Step 3: Make the caramel
In a medium saucepan, melt the butter over medium-low heat. Stir in brown sugar, ½ tsp fine sea salt, and vanilla extract until smooth. Let the mixture simmer gently without stirring for 5 minutes, adjusting heat as needed to maintain a steady bubble.
4Step 4: Add vinegar and cayenne
Still on the heat, stir in the white wine vinegar and cayenne pepper. Let bubble for 1 more minute.
5Step 5: Whisk in baking soda
Remove from heat and quickly whisk in the baking soda — the caramel will foam and lighten in color.
6Step 6: Combine
Immediately pour the caramel over the popcorn. Add toasted pecans and toss with a spatula until evenly coated.
7Step 7: Bake for crunch
Spread mixture on a parchment-lined baking sheet and bake at 250°F for 30 minutes, stirring halfway through.
8Step 8: Cool and Serve
After removing from the oven, sprinkle lightly with flaky sea salt. Let cool completely on the baking sheet before breaking into clusters. Store in an airtight container for up to five days.