Heat the oven to 250°F.
Make the syrup: In a medium pot over medium heat, heat the butter, syrup, sugar, oil, soy sauce, and salt, stirring, until the sugar is dissolved. Remove the pot from the heat to cool while you prepare the dry ingredients.
Make the snack mix: In a very large bowl (you might need two), combine the peanuts, Bugles, cereals, Goldfish, and pretzels, mixing bottom to top with your hands.
Carefully add the butter mixture to the bowl. Using gloved hands (optional), give everything a good mix, bottom to top. Once the mixture is sufficiently coated with the sauce, sprinkle half of the furikake over and toss until evenly coated. Sprinkle the remaining furikake over and toss again. Divide the cereal mixture between two half-sheet pans.
Bake, removing the pans every 15 to 20 minutes to toss, for about 1 hour, until the mixture is dry. The cooking time will depend on the humidity as well as how crispy you like your mix. (It has taken me up to 1½ hours on humid days.)
Transfer the pans to wire racks and let cool completely. Store in an airtight container or zip-top bags, or enjoy immediately and watch them disappear!
