Grease the crock of a slow cooker with nonstick cooking spray. Place 4 tortillas into the bottom, overlapping if necessary. Add half of beef mixture and 1/2 cup cheese on top of tortillas. Top with 4 tortillas.
Repeat with another layer of beef (using up the remaining mixture) and 1/2 cup cheese. Top with 4 tortillas and repeat with remaining beans, corn, green chilies and 1/2 cup of cheese and 1/3 of olives. Top with 4 tortillas and and sprinkle with 1/2 cup cheese and remaining black olives.