Place rice and 6 cups of water in a large saucepan; bring to a boil. Reduce heat to a medium-low and cook, covered, stirring often, until water is completely absorbed, 20 to 25 minutes. Transfer to a large bowl; set aside until completely cooled.
Meanwhile, in a small skillet heat olive oil over medium-high heat. Add garlic and cook, stirring, until golden and fragrant, about 2 minutes. Remove from heat; set aside.
Stir 3 eggs, one at a time, into cooled rice. Add Parmesan, parsley, and garlic powder; stir to combine. Season with salt and pepper.
Fill a large bowl with water. Dip your hands into the water and then form rice mixture into a 2 1/2-inch ball. Transfer to a parchment-lined baking sheet. Repeat process until all of the rice has been used. Using 2 fingers, make an indentation in each ball. Fill each ball with 1 piece of mozzarella cheese and 1 piece of capicolla or proscuitto. Press together to enclose. If necessary, add more rice mixture to cover.
Beat remaining 2 eggs in a medium bowl. Place breadcrumbs in a shallow dish. Dip each rice ball first in egg mixture, and then in breadcrumbs to coat. Gently remold rice balls if they begin to loose their round shape. Return to parchment paper-lined baking sheet; set aside.
Heat 5 inches of oil in a large Dutch-oven until it reaches 350 degrees on a deep-fry thermometer. Using a slotted spoon, gently lower one rice ball at a time into hot oil, working in batches if necessary. Cook rice balls, turning, until brown and crispy on all sides, 2 to 3 minutes. Transfer to a paper towel-lined plate. Serve immediately with marinara sauce (I have posted this!).