Lay pepperoni on 2 layers of paper towels. Microwave pepperoni for 20-30 seconds on high to render fat. Drain well and chop into small pieces.
Combine with sour cream, cheddar, cream cheese, mayonnaise and green onions. Season with red pepper if desired. Transfer mixture into a small baking dish.
Bake at 350 for 20 minutes or until heated through and bubbling. Serve with toasted baguette slices.