Line a baking sheet with parchment paper and set aside. In a large bowl add 1 tablespoon of the breadcrumbs to the rice with the egg, Parmigiano Reggiano, ¼ cup of the pesto, and the salt and pepper. Form the mixture into 16 equal-sized balls. Place the remaining bread crumbs in a bowl, roll the balls in the crumbs, arrange on the reserved baking sheet and chill for 1 hour (balls can also be made up to two days in advance and refrigerated until ready to use). During the last 15 minutes of chilling, fill a large saucepan halfway with oil until very hot but not smoking (if you’re using a candy or deep-fry thermometer, let the oil reach about 360°F). Test the oil’s readiness by dropping a small piece of bread into the oil; it should bubble, crisp, and turn golden almost immediately. Working in batches, fry the balls until golden, 2-3 minutes, allowing the oil to return to temperature between batches. Drain on paper towels and serve with the remaining pesto and the marinara sauce for dipping.