In a small bowl mix butter with garlic powder and Italian seasoning until blended.
Lightly spread butter on slider buns and place butter side down on a baking sheet.
Bake for 4-5 minutes until lightly toasted.
Place a piece of mozzarella on the bottom bun. Add basil leaves and top with meatball. Drizzle with sauce. Sprinkle with Parmesan cheese and top with slider bun.
Repeat with remaining meatballs.
Use a toothpick in the center of buns and meatballs to keep closed if desired.