Preheat oven to 400 F (200 C).
Fold 4 – 14 x 18 in (36 x 46 cm) sheets of parchment paper in half. Open up sheets and place an equal amount of onion, zucchini, and red pepper on one side of each sheet. Place salmon on top of vegetables. Drizzle lemon juice overtop. Fold empty half of parchment sheets over salmon and vegetables and crimp them shut. Place fish packets on 2 baking sheets and cook for 20 minutes. Let rest for 5 minutes before carefully opening packets.
Meanwhile, in skillet over medium, heat oil. Add garlic and ginger to pan and heat for 1 minute. Place blackberries, 1 tsp (5 mL) balsamic vinegar, thyme, honey, lemon zest, cinnamon, salt, black pepper, and chili powder, if using, in pan. Bring to boil, reduce heat to medium-low, and simmer, uncovered, for 15 minutes. Stir in remaining balsamic vinegar.
Serve salmon and vegetables topped with blackberry sauce and parsley.