Add the onion and garlic to the slow cooker and spread out to cover the whole bottom of the pot.
Trim excess fat off the pork. Cut the meat into 2 or 3 pieces if it’s too large to fit in your slow cooker. Add 1 teaspoon salt, 1 teaspoon cumin, 1 teaspoon smoked paprika, ½ teaspoon chili powder, ½ teaspoon sweet paprika, and ½ teaspoon black pepper to a small bowl and stir to combine. Rub the seasoning blend on all sides of the pork.
Add the pork to the slow cooker and pour in the orange juice, lime juice, and 1 cup broth. Add the two bay leaves.
Cover the slow cooker and cook on low for 8 to 10 hours or on high for 4 to 6 hours.
Remove the pork from the slow cooker and shred it with two forks or tongs.
If you want the carnitas extra crispy, add the shredded meat to a rimmed baking sheet and broil on high for 3 to 5 minutes (watch closely to make sure it doesn’t burn) to crisp the edges.