Position a rack in the center of the oven and preheat to 375 degrees F. Roll each piece of bread to thinly flatten.
Microwave the butter with a large pinch of salt in a small microwave-safe bowl until melted, about 1 minute. Brush both sides of each slice of bread with the butter.
Make the toast bowls: Gently press a slice of bread inside a cup of a 12- cup muffin tin. The bottom and sides of the bread should be flush against the cup; pleat the sides of the bread as needed to fit. Repeat with the remaining bread, filling every other muffin cup so that the bread bowls do not touch. Bake, rotating about halfway through, until lightly browned and crispy in spots, 12 to 15 minutes.
Meanwhile, whisk together the milk, eggs, a large pinch of salt and a few grinds of pepper in a large bowl.
Put the bacon in a medium nonstick skillet over medium heat. Cook, stirring occasionally, until the bacon is crispy, 12 to 15 minutes. Use a slotted spoon to transfer to a paper-towel-lined plate.
Keep the bacon drippings in the skillet and adjust the heat to low. Pour the egg mixture into the skillet. Cook the eggs, stirring and scraping the sides of the skillet as needed, until small curds form and the eggs are just set, 8 to 10 minutes. Remove from the heat and fold in the cheese until almost completely melted.
Divide the hot eggs among the toast bowls and top with the crispy bacon. Serve with hot sauce.