In small bowl, mix sugar, chili powder and red pepper; set aside.
In large microwavable bowl, microwave butter uncovered on High about 40 seconds or until melted. Stir in cereals and nuts until evenly coated. Stir in sugar mixture until evenly coated.
Microwave uncovered on High 5 to 6 minutes, stirring after 2 minutes, until mixture just begins to turn brown. Spread on waxed paper to cool. Store in airtight container.