Preheat oven to 250 degrees F,
Place the butter in a large baking dish. (I use 9x13 disposable aluminum pan with tall sides.) Set pan in the oven until butter is melted. Remove from the oven.
Whisk in the worcestershire sauce, seasoned salt, garlic powder, and onion powder.
Gently stir in the chex cereal to coat as much as possible. Return pan to the oven. Bake for 8 minutes, then stir, and return to oven for 8 more minutes. Repeat this 2 more times, for a total of 32 minutes.
Spread the Gardetto's snack mix in the center of a paper towel lined baking sheet. Remove the chex cereal from the oven, pour over the Gardetto's. Allow to cool for at least 1 hour.
Arrange the cashews, M&M's, cookies, candy corn, and pretzels.
Place into Ziploc bags for later use, fill snack bags, or arrange on Halloween themed party dishes.