Meatball Sandwich

Name: Meatball Sandwich
Prep time: 20 min
Cook time: 20 min
Total time: 40 min
Cuisine: American
Ingredients: 1 pound ground beef; 0.75 cup bread crumbs; 1 large egg, beaten; 2 cloves garlic, minced; 2 tablespoons grated Parmesan cheese; 2 tablespoons chopped fresh parsley; 2 teaspoons dried Italian seasoning; 1 French baguette; 1 tablespoon extra-virgin olive oil; 0.5 teaspoon garlic powder; 1 pinch salt, or to taste; 1 (14 ounce) jar spaghetti sauce; 4 slices provolone cheese