01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Combine ground beef, breadcrumbs, Parmesan, egg, minced garlic, parsley, oregano, salt, and pepper in a large bowl. Mix until just combined without overworking.
03 - Form mixture into 24 small meatballs, approximately 1 inch in diameter. Place on prepared baking sheet.
04 - Bake for 15-18 minutes until browned and cooked through.
05 - Toss bread cubes with olive oil and garlic powder. Arrange on separate baking sheet and toast for 6-8 minutes, turning once, until golden and crisp.
06 - Heat marinara sauce in a small saucepan over low heat.
07 - Thread one toasted bread cube, one meatball, a mozzarella ball, and another bread cube onto each skewer.
08 - Arrange skewers on serving platter. Drizzle with melted butter and sprinkle with fresh basil. Serve warm with extra marinara sauce for dipping.