Preheat the oven to 350 degrees F. Whisk the olive oil, Worcestershire sauce, hot sauce, garlic powder, cumin, onion powder, cayenne and 1/2 teaspoon salt in a bowl. Combine the rice cereal squares, cornflakes, pita chips and pepitas in a bowl. Toss with the spice mixture and spread on a baking sheet. Bake, stirring occasionally, until golden, about 40 minutes.