Bring orange juice, brown sugar, salt, garlic, thyme, bay leaves, peppercorns, cinnamon, and 6 cups water to a simmer in a large pot. Remove from heat. Cool to room temperature. Add pork and brine 12 hours.
Remove pork from brine and rinse under cold water. Pat pork dry with paper towels.
Preheat oven to 350F/180C. Heat oil in a large skillet over medium-high heat. Cook pork, in batches, turning once, until golden brown, 4 to 6 minutes. Transfer to a rimmed baking sheet. Bake until the internal temperature reaches 160F/70C 4 to 6 minutes. Let rest 5 minutes. Serve drizzled with glaze.
Make the Glaze:
Combine molasses, apple cider vinegar, and rosemary in a small saucepan. Cook over medium heat until reduced to 2/3 cup, 12 to 15 minutes.
Whisk in unsalted butter and bourbon; continue to cook until thickened, 1 to 2 minutes.
Season with kosher salt and black pepper.