In a large mixing bowl, combine ground beef, breadcrumbs, egg, chopped onion, garlic powder, salt, and black pepper. Mix gently until combined.

Scoop the mixture and shape it into 16 meatballs, each about 1½ inches in diameter.

In a large skillet, heat olive oil over medium heat. Add the meatballs and cook for 6–8 minutes until golden brown.

Pour barbecue sauce over the meatballs and let them simmer gently for about 5 minutes.

In a blender, combine avocado, Greek yogurt, mayonnaise, cilantro, lime juice, minced garlic, and water. Blend until smooth.

Divide cooked rice among four bowls. Top with corn, black beans, sliced red onion, and diced avocado before adding barbecue meatballs.

Drizzle avocado goddess sauce over each bowl and garnish with extra cilantro if desired. Serve immediately.