Pour off all but 1 tsp fat from skillet; add onions, 1 tsp brown sugar, 1/4 tsp salt, 1/4 cup water. Cook over medium-high heat until onions are soft, about 4-6 minutes. Stir in garlic and thyme and cook until fragrant, about 30 seconds. Pour onions over chops in the slow cooker. Add broth, soy sauce and remaining 1 Tbsp brown sugar to skillet, bring to a boil and add bay leaves. Pour mixture over onions in slow cooker. Cover slow cooker and cook on low until pork is tender, 8 hours (or high for 4 hours).

When ready to serve, transfer chops to platter. Discard bay leaves, strain liquid into a saucepan, reserving the solids. Transfer solids to a blender with 1 cup liquid and blend until smooth. Stir the blended mixture back into remaining liquid in the saucepan. In a small bowl, mix cornstarch and remaining 2 Tbsp water together and stir into sauce. Cook over medium heat until thickened, about 5 minutes. Stir in vinegar, season with salt and pepper, pour over chops and sprinkle with reserved bacon and parsley. Serve.