Preheat oven to 375°F (190°C).
In a bowl, combine brown sugar, chili powder, cumin, cinnamon, salt, and pepper.
Press each pork medallion into the sugar-spice mix to coat all sides.
Heat olive oil in an oven-safe skillet over medium-high heat.
Sear medallions for 2–3 minutes per side until nicely browned.
If using, sprinkle chopped pecans on top of the medallions.
Transfer the skillet to the oven and roast for 10–12 minutes.
Remove from oven and let rest for 5–10 minutes before serving.
