Preheat oven to 350°.
In a small bowl, mix cream cheese and 1 ½ teaspoons basil until blended; spread onto six stale bread slices. Top with fresh mozzarella cheese and remaining bread slices. Spread outsides of sandwiches with butter. Arrange, slightly overlapping, in a greased 13×9” baking dish.
In a small saucepan, combine tomato paste, garlic, salt, pepper and remaining basil; cook and stir over medium heat, for 1 minute. Gradually whisk in milk and bring to a boil. Reduce heat; simmer, uncovered, 4-5 minutes or until thickened, stirring frequently. Taste for seasoning; add additional dried basil, salt, or pepper as needed. Remove from heat.
Whisk eggs in a large bowl; gradually whisk in 1/3 of the soup mixture, then stir in the remaining. Pour mixture over the layered sandwiches. Sprinkle with shredded cheese blend.
Bake, uncovered, 25-30 minutes or until golden brown and cheese is melted. Let stand 10 minutes before serving.
Recipe adapted from: www.tasteofhome.com