Line a 3 1/2- or 4-quart oval slow cooker with a double thickness of pan lining paper, parchment sides facing the food. In a small bowl combine Parmesan cheese and Italian seasoning. In another small bowl whisk together the butter and pesto.
Pull and pinch each dough piece into a ball. Arrange 10 balls in paper-lined slow cooker, starting in the center and working toward the edges, leaving a little space between pieces. Sprinkle with half of the cheese mixture and half of the butter mixture. Repeat layers.
Cover and cook on high for 1 1/2 hours; rotate the removable crockery liner. Cover and cook 40 to 50 minutes more or until an instant-read thermometer inserted in the center registers 200 degrees F. Using the edges of the pan lining paper, remove bread to a wire rack to cool slightly. Serve bread warm and, if desired, with marinara sauce.