Brown ground beef, drain off fat. Mix in 1 can of sauce and the refried beans. Blend well.
Spray a casserole dish (9x13)with non-stick spray. Tear tortillas in strips, place a layer on the bottom of the pan. Spoon some of the meat mixture over the bottom of the pan. Sprinkle a layer of grated cheese. Repeat for one more layer, using the remaining meat mixture. Put a final layer of tortillas over the top. Cover with more cheese. Pour last can of sauce over top.
Bake @ 350 for approx 30 minutes, or until cheese is melted and sauce is bubbly.