Preheat oven to 375 degrees Fahrenheit.
Spray casserole dish with cooking spray lightly.
Cook beef in a skillet until no longer pink.
Add onions and bell peppers, cook for five minutes.
Stir in Worcestershire sauce, garlic powder, onion powder, salt.
Remove skillet from heat and stir in peas.
Transfer meat mixture to the prepared casserole dish.
Spread BBQ sauce over the meat mixture evenly.
In a bowl, mix mashed potatoes, milk, and butter.
Spread mashed potatoes over meat layer in the dish.
Sprinkle cheddar and mozzarella cheese on top evenly.
Add cooked bacon bits over the cheesy top layer.
Cover casserole with foil and bake for twenty minutes.
Remove foil and bake for another ten minutes.
Let cheesy loaded meatloaf casserole recipe rest before serving.