In a medium bowl, combine the pepper jack cheese, spinach, salt and pepper.
Spoon about 1/4c of the spinach mixture into each chicken breast. Roll each chicken breast tightly and fasten seams with several toothpicks. Place on a foil lined pan seam side up.
Brush each chicken breast with olive oil. Sprinkle bread crumbs evenly over the chicken.
Bake for 35-40min or until chicken is cooked through. Remove toothpicks before serving.