In 10-inch skillet, cook sausage over medium-high heat 5 to 7 minutes, stirring occasionally, until no longer pink; drain.
Spray 13x9-inch (3-quart) glass baking dish with cooking spray. Spread bread in baking dish. Spread cooked sausage evenly over bread. Sprinkle evenly with 1 1/2 cups of the cheese and the tomatoes.
In medium bowl, beat eggs, milk, basil, mustard and salt with fork or wire whisk; pour over tomatoes. Sprinkle with remaining 1/2 cup cheese. Cover tightly; refrigerate at least 2 hours but no longer than 24 hours.
Heat oven to 350°F. Uncover baking dish; bake 35 to 40 minutes or until knife inserted in center comes out clean.