Prepare the slow cooker with nonstick cooking spray.
In a medium skillet, cook the ground beef with the onion and bell peppers, crumbling the beef as it cooks until the beef is no longer pink. Drain well and transfer to the slow cooker.
Add the frozen corn, taco seasoning, and tomato sauce to the slow cooker. Stir to combine.
Cover and cook on low for 3 to 4 hours.
Prepare the batter.
Top the beef mixture with the cheese and spoon the batter over the top.
Cover and switch the slow cooker to high. Continue cooking for 1 hour or until the cornbread layer is cooked through and no longer runny.