Preheat your oven to 425°F and line two baking sheets with parchment paper. While the oven heats, toss Brussels sprouts, butternut squash, and red onion with 2 tbsp olive oil, garlic powder, smoked paprika, cayenne, salt, and pepper.
Spread vegetables in a single layer on one baking sheet, then slide into the oven. Set a timer for 18-20 minutes until the vegetables are deeply caramelized and tender at the edges.
Pat salmon fillets dry with paper towels, then place on the second baking sheet skin-side down. Brush with remaining 1 tbsp olive oil and season generously with salt, pepper, and fresh thyme sprigs.
When vegetables have roasted for 10 minutes, add the salmon sheet to the oven on the rack above. Bake for exactly 8-10 minutes until salmon flakes easily with a fork—don't overcook it. This timing ensures the hearty fall salmon bowl recipe finishes with perfectly moist fish and caramelized vegetables.
While everything roasts, whisk together balsamic vinegar and maple syrup in a small bowl. Divide cooked quinoa among four bowls, then top each with roasted vegetables and salmon fillet.
Drizzle the balsamic-maple glaze over the bowl, then scatter cranberries, pumpkin seeds, and additional thyme on top. Serve immediately while the salmon is warm and the vegetables still have their crispy edges—the contrast is what makes this autumn bowl special.