Preheat oven to 375 F.
Spray an 8x8 inch pan.
Mix black beans and refried beans together.
Spread bean mixture in the bottom of prepared pan.
Spread sour cream on top of bean mixture.
Pour taco sauce on top of sour cream.
Sprinkle cheese on top.
Cook for 25-30 minutes until bubbly.
Serve with your favorite chips.