Preheat oven to 350°F. Lightly coat a 13- x 9-inch baking dish with cooking spray.
Whisk together eggs, Monterey Jack cheese, milk, salt, and pepper in a large bowl.
Arrange Tater Tots in an even layer in baking dish.
Pour egg mixture evenly over Tater Tots. Top evenly with Cheddar cheese.
Bake in preheated oven until set and cheese is golden brown, 40 to 45 minutes.
Let stand 10 minutes. Sprinkle with crumbled bacon.
