Prepare the Pork Carnitas: Preheat oven to 300°F (150°C) or prepare a slow cooker. Rub pork chunks with salt, pepper, cumin, smoked paprika, chili powder, and garlic powder. Place pork in a roasting pan or slow cooker. Add orange juice, lime juice, onion, garlic, and bay leaf.
Cook the Pork: Oven Method: Cover with foil and bake for 1.5 hours, until tender. Slow Cooker Method: Cook on low for 6–7 hours or until pork is tender.
Shred and Crisp the Pork: Remove pork from pan and shred with two forks. Optional: For crispy edges, spread shredded pork on a baking sheet and broil for 5–7 minutes until slightly browned and crispy.
Prepare the Cilantro Rice: Rinse rice under cold water until water runs clear. Combine rice and water (or broth) in a saucepan; bring to a boil. Reduce heat, cover, and simmer 15–18 minutes until rice is cooked. Remove from heat, fluff with a fork, then stir in cilantro, lime juice, olive oil, and salt to taste.
Assemble the Burrito Bowls: Divide cilantro rice among 4 bowls. Top with shredded pork carnitas, black beans, corn, tomatoes, avocado, and any other desired toppings. Garnish with lime wedges and extra cilantro if desired.