Preheat the oven to 250ºF and lightly coat a baking sheet or roasting pan with cooking spray.

In a large bowl, combine 8 cups of Crispix cereal and 2 cups of pecan halves.

In a medium saucepan, heat ½ cup of dark brown sugar, ½ cup of light corn syrup, and ½ cup of salted butter over medium-high heat. Bring the mixture to a boil, stirring occasionally. Once boiling, remove from heat and stir in 1 teaspoon of vanilla extract and ½ teaspoon of baking soda.

Pour the caramel mixture over the cereal and pecans, tossing gently to coat everything evenly.

Spread the coated cereal mixture evenly onto the prepared baking sheet. Bake for 1 hour, stirring every 15 minutes.

Once baked, transfer the mixture onto wax or parchment paper to cool. Break into pieces before serving.