Ravioli with Balsamic Brown Butter Sauce

20 oz frozen ravioli
6 T butter
2 T balsamic vinegar
¼ C shredded parmesan cheese

Cook ravioli according to package directions. Place butter in a skillet and cook over medium heat, stirring frequently until dark brown. Remove from heat and stir in vinegar. Toss with ravioli and stir in parmesan.