01 -
Preheat oven to 400°F.
02 -
Cook ground beef in a large frying pan over medium-high heat with a dab of butter or margarine. Crumble the ground beef well while it's cooking.
03 -
Once the ground beef is cooked, drain excess grease from the pan. Add the diced onions to the pan with the ground beef and stir well. Continue cooking for a few minutes, stirring occasionally.
04 -
Remove the pan from the heat. Add bacon bits, mayonnaise, ketchup, mustard, salt, pepper, and onion powder. Stir well to combine.
05 -
Spread 6 slices of bread with 1/4 cup margarine and then cut them in half. Lay the pieces of bread, margarine side down, in a greased 9 x 13 inch baking dish.
06 -
Sprinkle 2 cups of the shredded cheese on top of the bread layer.
07 -
Spoon the meat mixture on top of the cheese and spread it out evenly.
08 -
Sprinkle the remaining 2 cups of cheese over the meat mixture.
09 -
Spread 6 more slices of bread with 1/4 cup margarine and cut them in half. Lay the pieces of bread, margarine side up, on top of the casserole.
10 -
Place the dish in the oven and bake for 20–24 minutes, until the top layer of bread is golden brown.
11 -
Remove the casserole from the oven and let cool slightly before serving. Enjoy!