Preheat your oven to 400°F (200°C). Line a large rimmed baking sheet or roasting pan with parchment paper or foil for easy cleanup.
Pat the chicken leg quarters very dry with paper towels. This step is crucial for crispy skin. Season liberally on all sides with the salt and black pepper.
In a medium bowl, whisk together the maple syrup, fresh orange juice, orange zest, soy sauce, Dijon mustard, minced garlic, and olive oil until smooth.
Place the chicken skin-side up on the prepared baking sheet. Pour approximately half of the glaze mixture over the chicken, ensuring the pieces are well coated.
Arrange the fresh thyme sprigs around and on top of the chicken.
Roast in the preheated oven for 45 to 50 minutes. Every 15 minutes, open the oven and baste the chicken generously with the pan juices and the remaining reserved glaze.
Check the internal temperature with a meat thermometer; it should read 165°F (74°C) at the thickest part of the thigh.
For extra color, switch the oven to broil for the last 2-3 minutes, watching closely to prevent the sugary glaze from burning.
Remove from the oven and let rest for 5-10 minutes. Garnish with fresh orange slices and extra thyme before serving.