Preheat oven to 300 degrees and line a baking sheet with parchment paper.

Combine the chex cereal, pretzels, Cheez Itz, oyster crackers in a large bowl and set aside.

Heat a small saucepan over medium heat and add butter. Whisk constantly until the butter is boiling and small brown bits appear at the bottom of the pan (about 6 minutes). When this happens, remove from the heat immediately and pour into a separate bowl.

Whisk in the parmesan seasoning. The mixture will get thicker at this points. Pour over bowl of mix and stir until combined, at least 5 minutes. To ensure it's all completely coated.

Spread the mixture on a baking sheet and sprinkle with the parmesan cheese.

Bake in the preheated oven for one hour, tossing every 15 minutes. Remove from the oven and let it cool. Store in an air tight container for up to 5 days.