Prepare the grill or the oven to cook indirect at 325°F. In a large bowl, break up the ground beef. Top with the egg, rub, cheese, and parsley. Mix well. Add the bread crumbs and mix well. Divide and form into 8 meatballs, all the same size. If you’re cooking on the grill, place the meatballs on a perforated grid; for the oven, place them on a baking sheet. Cook the meatballs for 20 minutes or until they are golden brown. Set aside.

In a large saucepan, melt the butter over medium heat. Add the onion, jalapeño, and garlic and sauté for 3-4 minutes until the onion is translucent. Add the tomatoes, barbecue sauce, brown sugar, and barbecue rub. Mix well and bring to a simmer. Cook, uncovered, for 5 minutes, stirring occasionally.

Add the meatballs to the sauce. Stir to coat and cook for 10 minutes, stirring occasionally. Meanwhile, cook the spaghetti as directed on the package. Drain the pasta and serve topped with the sauce and meatballs. Garnish with additional finely grated cheddar cheese and chopped parsley, if desired.