Start by popping your popcorn and transferring it to a large mixing bowl. Remove any unpopped kernels. Crush the kettle chips until you have about 2 1/2 cups, then add them to the bowl and gently toss to combine.
In a medium saucepan, melt the unsalted butter over medium heat. Stir in the packed light brown sugar and corn syrup, cooking while stirring until it comes to a gentle boil. Boil for 4-5 minutes without stirring until it turns amber.
Remove from heat and carefully stir in the vanilla extract and baking soda. Be cautious as the mixture will bubble up. Stir until well combined.
Pour the hot caramel sauce over the popcorn and kettle chips. Using a spatula, gently fold everything together until evenly coated.
Preheat your oven to 250°F (120°C). Spread the mixture onto a baking sheet lined with parchment paper. Bake for 45 minutes, stirring every 15 minutes until golden and crunchy.
Allow it to cool slightly. If using chocolate chips, melt them in 30-second intervals in a microwave-safe bowl. Drizzle over the popcorn and sprinkle with optional sprinkles.
Let the chocolate set before breaking the popcorn into pieces. Serve in a bowl or package as a gift.
