Step 1

Grease a 9x13-inch baking dish with baking spray or butter.

Step 2

In a large skillet, brown the sausage over medium heat until crumbly and no longer pink, about 10 minutes. Drain well.

Step 3

Cut the crusts off the bread, and slice them in half. Arrange the slices in a single layer in the greased baking dish. Cut the pieces, if necessary, to fit the dish.

Step 4

Sprinkle the bread with sausage crumbles followed by shredded cheese.

Step 5

In a large bowl, beat together eggs, milk, mustard, pepper, and salt until well-combined. Pour the mixture over the cheese. Cover the dish with plastic wrap and refrigerate for 8 hours.

Step 6

Preheat the oven to 350 degrees Fahrenheit. Let the casserole sit at room temperature for 30 minutes.

Step 7

Remove the plastic wrap and bake the casserole for 40 minutes, or until golden. Let it rest for 10 minutes before serving. Enjoy!