Preheat the oven to 350°F (175°C).
Slice the French bread horizontally in half. Spread the 1/3 cup Challenge spreadable butter evenly over the cut surfaces of both halves.
Sprinkle the garlic salt and Italian seasonings evenly over the buttered bread.
Place the bread on a baking sheet and bake for 8–10 minutes until the butter is melted; then broil for about 1 minute to brown and crisp the edges (watch closely to avoid burning).
While the bread bakes, trim the bottom 1–2 inches from the romaine hearts to remove the core, then chop the lettuce into bite-sized pieces and transfer to a large bowl.
Toss the chopped romaine with the 1/3 cup creamy Caesar dressing until evenly coated. Stir in the 2 cups shredded chicken and 1/4 cup shaved Parmesan until combined.
Use tongs to spread the chicken Caesar salad evenly along the length of the bottom half of the garlic bread. Place the top half on, then cut into 4–6 large sandwiches or 8–12 smaller sandwiches as desired. Serve immediately.
