Spicy Pork Tenderloin with Ginger-Maple Sauce

adapted from Cooking Light

2 teaspoons chili powder
1 ¼ teaspoons salt
1 teaspoon black pepper
1 teaspoon ground cinnamon
1 ½ lbs. pork tenderloin, trimmed
Cooking spray
2 tablespoons butter
1 cup chopped onion
2 tablespoons bottled ground fresh ginger
1 cup chicken broth
½ cup maple syrup

Preheat oven to 375°. Combine first 4 ingredients in a small bowl; rub pork with spice mixture. Heat a large ovenproof skillet coated with cooking spray over medium-high heat; add pork. Cook 6 minutes; brown on all sides. Place skillet in oven; for 30 minutes. Let stand 10 minutes before slicing.

While pork bakes, melt the butter in a medium saucepan over medium-high heat. Add the onion, and cook 10 minutes or until golden brown, stirring frequently. Add ginger, and cook 4 minutes. Stir in broth and syrup, scraping pan to loosen browned bits. Bring broth mixture to a boil; cook until reduced to 3/4 cup (about 10 minutes). Cut pork into 1/4-inch-thick slices; serve with sauce.