PREHEAT oven to 275℉ (135°C). Mix popcorn and peanuts in large bowl. Set aside.
HEAT butter and RedHot Sauce in medium saucepan on medium heat until butter is melted, stirring to mix well. Stir in brown sugar and corn syrup. Bring to boil, stirring constantly. Boil 6 minutes without stirring.
POUR RedHot caramel mixture over popcorn and peanuts. Toss to coat evenly with spatula sprayed with no stick cooking spray. Spread evenly on parchment-lined shallow baking pan.
BAKE 45 minutes, stirring every 15 minutes. Cool completely on wire rack. Break into clusters. Store in airtight container.