Cook broccoli in boiling water 10 minutes or until tender. Drain. Spread one side of each bread slice with 1 teaspoon butter.
Arrange 2 slices bread, butter side up in greased 1-quart casserole. Layer cheese, broccoli, and remaining 2 bread slices, butter side down.
Beat together eggs, milk, salt, hot pepper sauce and pepper in medium bowl. Gradually pour over bread.
Place small wire rack in 5-quart slow cooker. Pour in 1 cup water. place casserole on rack. Cover and cook on high 3 hours in crock pot.