Preheat oven to 400°F. Lightly grease a 9x13 inch baking dish. Place each chicken breast between two sheets of plastic wrap and pound to 1/2-inch thickness. In a small bowl, combine olive oil, Cajun seasoning, garlic powder, smoked paprika, salt, and pepper. Brush the mixture evenly over both sides of the chicken breasts.

In a medium bowl, combine the squeezed spinach, chopped roasted red peppers, 1/2 cup shredded mozzarella cheese, ricotta cheese, Parmesan cheese, and beaten egg. Mix well.

Spread about 1/4 of the spinach mixture evenly over each chicken breast. Roll up tightly and secure with toothpicks.

Heat the butter in a large oven-safe skillet over medium-high heat. Sear the chicken rolls on all sides until golden brown, about 2-3 minutes per side.

In a small saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1 minute, stirring constantly. Gradually whisk in the chicken broth and milk until smooth. Bring to a simmer, stirring constantly, until the sauce has thickened. Stir in the heavy cream and remaining 1/2 cup mozzarella cheese until melted and smooth. Season with salt and pepper to taste.

Pour the cheese sauce over the seared chicken rolls in the skillet. Transfer the skillet to the preheated oven and bake for 20-25 minutes, or until the chicken is cooked through and the internal temperature reaches 165°F (74°C).

Remove from oven and let rest for 5 minutes before serving. Remove toothpicks before serving. Spoon extra sauce over chicken if desired.