Preheat your oven to 300°F (150°C).

In a large mixing bowl, combine Rice Chex, Wheat Chex, pretzel sticks, pecans, and dried cranberries.

In a saucepan over medium heat, melt butter and then stir in brown sugar, pumpkin puree, pumpkin pie spice, and vanilla extract until smooth.

Pour the pumpkin spice mixture over the Chex mix and stir until coated.

Spread the mixture evenly on a lined baking sheet.

Bake for 45 minutes, stirring every 15 minutes.

Let the mix cool completely on the baking sheet before storing or enjoying.