Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup. This temperature ensures the salmon cooks through while vegetables caramelize without burning during the bake time.

In a small bowl, whisk together maple syrup, Dijon mustard, balsamic vinegar, olive oil, garlic powder, smoked paprika, salt, and pepper until fully combined. This glaze mixture is the flavor foundation for your entire meal and should look like a thick honey consistency.

Arrange Brussels sprouts, carrots, bell pepper, and red onion on the prepared sheet pan in a single layer. Drizzle vegetables with lemon juice and half the glaze mixture, tossing gently to coat evenly.

Roast vegetables for 8 minutes at 400°F, allowing them to start softening before adding the salmon. This head start ensures the loaded sheet pan maple salmon recipe finishes perfectly synchronized with the vegetables.

Remove the sheet pan from the oven and nestle the salmon fillets among the roasted vegetables. Brush the remaining glaze directly onto each fillet, then sprinkle fresh thyme over the entire pan.

Return to the oven for exactly 12 minutes, until salmon flakes easily with a fork and reaches 145°F internally. The maple-glazed salmon skin should appear slightly caramelized while flesh remains moist inside.

Let the pan rest for 2 minutes before serving, allowing residual heat to finish the cooking process gently. Fresh lemon wedges squeezed over individual plates brighten the rich maple flavors beautifully.