Preheat the oven to 275°F. Line a large (18x26 inch) rimmed baking sheet with parchment paper and set aside.

Mix together in a small bowl the granulated sugar and cinnamon. Set aside.

To a large bowl add the rice Chex cereal, corn Chex cereal, and pretzel sticks.

In a separate bowl, stir together the melted butter, light brown sugar and vanilla extract until the sugar has dissolved.

Pour the butter mixture over the cereal and pretzels and stir gently to combine without crushing the cereal.

Sprinkle the reserved cinnamon sugar over the butter coated cereal and gently toss to evenly coat all the cereal and pretzels with the cinnamon sugar mixture.

Transfer to the prepared baking sheet and spread the mixture out into an even layer.

Bake in the center rack of the preheated oven for 15 minutes, remove from the oven and stir. Return the baking sheet to the oven and bake for an additional 15 minutes. Stir then bake for a final 15 minutes, for a total bake time of 45 minutes. This method helps to ensure that all sides of the coated cereal are evenly crisped and does not burn.

Remove the baking sheet from the oven and allow the mixture to cool in the pan for 15 minutes before adding the quartered caramel candies. Gently toss to evenly distribute all the caramels into the cereal mixture.

Transfer the churro chex mix to a large bowl for immediate serving.