Mix together all ingredients and pour over tilapia. Cover and refrigerate for at least 15 minutes.
Line a baking sheet with foil and preheat broiler. Lightly spray foil with baking spray, and arrange tilapia in a single layer, saving marinade. Broil 5 minutes on each side. Meanwhile, in a small pan on the stovetop, bring marinade to a boil. Boil and stir for about 2 minutes, then lower the heat to simmer. Simmer until thickened. Serve tilapia with marinade while hot from the broiler.