Pimento Cheese French Bread Pizza

Name: Pimento Cheese French Bread Pizza
Ingredients: 2 ounces cream cheese, at room temperature; 3 tablespoons mayonnaise; 1/4 teaspoon onion powder; 1/8 teaspoon cayenne pepper; Kosher salt and freshly ground black pepper; 4 ounces extra-sharp Cheddar cheese, grated; 2 tablespoons drained diced pimentos (about half of a 4-ounce jar); 1 baguette; 3 ounces sliced pepperoni (slices halved or quartered if large); 2 cups shredded mozzarella cheese; 2 tablespoons finely chopped fresh parsley; Grated Parmesan cheese, for topping