Preheat oven to 250°F. Line a rimmed baking sheet or lasagna pan with parchment paper and set aside.
Combine all cereals, pretzels, and nuts in a large bowl.
3 cups Crispix cereal, 3 cups Rice Chex cereal, 3 cups Honey Chex cereal, 1 cup Cheerios cereal, 1 cup Honey Nut Cheerios cereal, 1 cup Pretzel Goldfish, 2-3 cups whole cashews
In a medium saucepan set over low heat, melt the butter. Add the Worcestershire sauce and seasoning salt (and cayenne if using) and mix well.
¾ cup unsalted butter, 3 tablespoons Worcestershire Sauce, 1½ teaspoons seasoning salt, 1 teaspoon ground cayenne pepper
Pour the butter mixture over the cereal and gently stir until everything is evenly coated.
Spread the cereal onto the prepared baking sheet.
Bake for 45-60 minutes - stirring every 15 minutes until it turns a little golden.
Pour out onto aluminum foil and let cool completely.