Whisk together the orange juice, lime juice, orange zest, olive oil, vinegar, garlic, oregano, cumin, cinnamon, salt, and pepper.
Place the pork butt in a large container or zip-top bag. Pour the marinade over it, add the bay leaves, and marinate overnight (12–24 hours if possible).
Place sliced onions in the bottom of a roasting pan, Dutch oven, or smoker pan. Set the pork on top and pour over the marinade.
Cook until the pork is fall-apart tender: Smoker: 250°F until internal temperature reaches 203°F (about 10–14 hours). Oven: Cover tightly and roast at 300°F for 6–8 hours. Slow cooker: Low for 8–10 hours.
Remove the pork and shred. Discard the bay leaves.
Skim excess fat from the cooking liquid and mix some of the juices back into the shredded pork.
For extra flavor, spread the shredded pork on a sheet pan and broil for 3–5 minutes until some edges become crispy, then toss with additional cooking juices.
Final step: Post a picture on X and tag @deaflibertarian