Preheat oven to 300 degrees F. Line 2 large rimmed baking sheets with parchment paper; set aside.
In a large bowl, combine 3 cups pretzels, 2 cups nuts, and 3 cups cheese crackers. Melt 6 tablespoons of butter in the microwave. In a small bowl, combine the melted butter, 1/3 cup buffalo sauce, 1 tablespoon grated parmesan cheese, and 2 tablespoons dry ranch powder seasoning. Pour mixture over snack mix and toss well with 2 large cooking spoons. Spread mixture onto a large rimmed baking sheet with parchment paper.
In a large bowl, pour 5 cups Chex cereal. In a bowl, melt 2 tablespoons butter. Combine butter with 1/3 cup buffalo sauce, 1 tablespoon grated parmesan cheese and 1 tablespoon dry ranch powder seasoning. Pour mixture over Chex cereal then toss with 2 large cooking spoons to coat well. Pour mixture onto second prepared baking sheet.
Sprinkle both sheet pans with 1 tablespoon dried parsley.
Bake in oven for 50 minutes. Halfway through baking, stir both mixtures and rotate the sheet pans to ensure even baking.
Allow to cool at least 10 minutes. During this time, the snack mix will firm up.
Pour into an air-tight storage container.