Preheat the oven to 350 degrees F. Spray a baking sheet with vegetable oil cooking spray. Set aside.
In a food processor, pulse together the shallots, sun-dried tomatoes, basil, shredded mozzarella, Parmesan, tomato paste, red pepper flakes, and salt. Process until blended. Transfer the mixture to a large bowl. Add the beef and pork and, using a wooden spoon or clean hands, stir until well combined. Form the mixture into 36 equal-size meatballs (about 1 1/4 to 1 1/2 inches in diameter).
Insert 1 cube smoked mozzarella cheese into the center of each meatball and form the meat around it, completely enclosing the cheese.
In a large nonstick skillet, heat half the oil over medium heat. Add half of the meatballs and cook, turning occasionally, until well browned on all sides, about 5 minutes. Drain on paper towels. Repeat with the remaining oil and meatballs.
Place the browned meatballs onto the prepared baking sheet. Bake for 8 to 10 minutes for medium doneness. Set aside to cool slightly, and serve with warm marinara sauce.