Preheat the oven to 250 degrees F.
In a very large bowl, mix together the cereals, pretzels, and nuts. (Stir in an extra cup or so of optional add-ins now, if using.)
In a small bowl or glass measuring cup, mix together the melted butter, Worcestershire sauce, salt, garlic powder, onion powder, and optional Tabasco sauce.
Drizzle the butter mixture evenly over the cereal mixture, stirring as you pour. Continue to gently stir until the dry ingredients are evenly coated by the wet mixture. (For less breakage when stirring, a curved spatula or “spoonula” works well.)
Transfer the mixture to a large roasting pan or two rimmed baking sheets. Bake for 1 hour, stirring every 15 minutes.
Cool thoroughly, and then store in airtight container.