Preheat oven to 250°F. Spray a large roasting pan with cooking spray. Combine cereal, pretzels, tortilla chips, crackers and peanuts in the roasting pan.
Melt butter in a medium saucepan. Add corn syrup, brown sugar and taco seasoning mix. Bring to a boil over medium-heat, stirring constantly.
Pour over cereal mixture; tossing to coat well. Bake 1 hour, stirring every 15 minutes. Cool, stirring frequently. Store in tightly covered container.