To prepare sauce, combine the first 6 ingredients in a medium saucepan; bring mixture to a boil. Reduce heat to medium; cook until reduced to 1/2 cup (about 11 minutes), stirring frequently. Remove from heat.
To prepare pork, combine chili powder, cinnamon, allspice, and salt, stirring well; rub evenly over pork. Cut pork crosswise into 12 slices.
Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add pork to pan; cook 4 minutes on each side or until desired degree of doneness. Serve with sauce.