Preheat oven to 350˚F.
Place all ingredients into a large mixing bowl and stir together until just combined.
Using meat mixture, roll 4 tablespoon sized meatballs (about 2 ounces each) until all the mixture has been used.
Add oil to a heavy bottom skillet and place over medium-high heat. Add meatballs to skillet (in two batches as to not overcrowd the pan) and brown on all sides, 2 to 3 minutes.
Add all meatballs back into skillet and place in oven until meatballs just cook though, 6 to 8 minutes.
Remove meatballs from oven and drain as much excess grease from skillet. Pour marinara sauce over meatballs and simmer for 5 minutes.
To assemble: Spoon a small amount of marinara sauce into each split baguette. Fill each with meatballs and top with more sauce. Finish with slices of provolone and broil on high for 2 to 3 minutes or until cheese has melted and is bubbling. Top with more marinara if desired, cracked black pepper and freshly grated Parmesan. Serve immediately.