Preheat the oven to 375 F and line a baking sheet with parchment paper.
In a large bowl, mix together ground beef, breadcrumbs, eggs, garlic powder, onion powder, ketchup, salt, and pepper, until well combined.
Take a spoonful of mixture and shape it between your hands into a 1 and 1⁄2-inch meatball, then place it onto the prepared baking sheet. Repeat with remaining mixture.
Bake for 12-15 minutes, or until meatballs are browned and cooked through.
Meanwhile, place all the ingredients for the sauce in a small saucepan and bring to a boil over medium heat, whisking continuously. Reduce heat and simmer for 8 to 10 minutes, or until is reduced and thick.
Once cooked, remove meatballs from the oven and pour over the sauce. Toss to coat.
To assemble the meal prep bowls, divide the cooked brown rice among 4 containers. Top with glazed meatballs, and garnish with green onions and sesame seeds.
Refrigerate for up to 5 days and reheat just before serving. Enjoy!