Preheat oven to 300°F. Line a heavy large baking sheet with a silicone liner or foil. Combine the pecans, walnuts and pumpkin seeds in a medium bowl. Stir the brown sugar, oil, water, chili powder and salt to blend in a small bowl. Drizzle 2 tablespoons of the brown sugar mixture over the nut mixture and toss to coat. Spread the nut mixture out into a single layer on the prepared baking sheet. Bake the nut mixture until it's beginning to turn golden brown, about 10 minutes.
Meanwhile: Toss the cereal and cranberries with the remaining brown sugar mixture in the same bowl (no need to wash). Add the cereal mixture to the nut mixture on the pan and spread out into a single layer. Roast in the oven until golden brown and glazed, about 12 minutes longer. Cool completely. Toss to combine. Transfer to jars and seal tightly. (Mix can be made up to 2 weeks ahead.)