Heat the oven to 375°.
Cook the beef in the skillet over medium heat 8 to 10 minutes, stirring occasionally, until brown; drain.
Rinse and drain the beans in a strainer. Mix the beef, beans, tomato sauce, salsa and chili powder in the ungreased baking pan.
Cover with lid or aluminum foil and bake 40 to 45 minutes, stirring once or twice, until hot and bubbly. Carefully remove the lid, and sprinkle cheese over the top. Continue baking uncovered about 5 minutes or until the cheese is melted.