01 - Set the oven to 375°F (190°C) and allow it to reach temperature.
02 - Pat pork loin dry using paper towels. Season evenly with kosher salt, black pepper, and olive oil.
03 - Position the seasoned pork loin on a rack within a roasting pan.
04 - In a saucepan, combine cranberries, orange juice, brown sugar, honey, orange zest, Dijon mustard, minced garlic, thyme, cinnamon, allspice, and a pinch of salt. Bring to a simmer over medium heat; cook 8–10 minutes, stirring, until cranberries burst and the mixture thickens.
05 - Transfer 1/2 cup of glaze to a bowl for serving.
06 - Brush half of the remaining glaze over the pork loin for initial flavoring.
07 - Roast pork for 60–75 minutes, basting every 20 minutes with additional glaze. Cook until the meat thermometer registers an internal temperature of 145°F (63°C).
08 - Remove from oven and tent loosely with foil. Let rest for 10 minutes to retain juices.
09 - Slice pork loin and serve with reserved cranberry orange glaze. Garnish with fresh rosemary and orange slices if desired.