In a food processor, combine the onion, garlic cloves, sofrito, orange juice, lime juice, adobo, sazón, thyme, oregano, cumin, salt, and black pepper. Blend until smooth and set aside.
Use your hands to separate the skin from the breast and the rest of the turkey. Pour the marinade all over the skin making sure to coat it thoroughly, including under the skin and inside the cavity.
Place the turkey in a large container, cover with foil or saran wrap, then place in the refrigerator to marinate overnight.
The next day, preheat the oven to 425°F.
Place the turkey in a roasting pan with a rack, season the skin with adobo and sazón, and add the butter cubes all over the turkey, including under the skin and inside the cavity.
Cover it tightly with foil and roast for 4 hours, using a turkey baster every 2 hours to scoop up the juices and pour them over the turkey.
Remove the foil and continue roasting for an additional 30 minute, or until the internal temperature reaches 165°F and the turkey is golden brown.
Let the turkey rest before carving. Buen provecho!