In a medium bowl, whisk to combine the eggs, milk, hot sauce (if using), salt, and pepper.

In a medium nonstick skillet, melt 2 teaspoons of butter over medium heat. Once the skillet is hot, add the eggs. Let them cook undisturbed for 20 to 30 seconds, or until the eggs are partially set. With a silicone spatula, stir gently and turn the eggs over periodically to form large curds, for about 1 more minute. Once the egg looks dry in most places, transfer to a plate. Remove the skillet from the heat, let it cool slightly, then wipe it clean.

Arrange two of the tortillas on a cutting board. Sprinkle about half the cheese over the top of both. Divide the scrambled eggs between the two, breaking them into bite-sized pieces. Sprinkle evenly with the bacon, cilantro, if using, and remaining cheese, and top each with another tortilla.

Return the pan to medium heat. Melt the remaining teaspoon of butter. Cook the quesadillas one at a time for 3 to 5 minutes each, flipping halfway through or when each side is golden brown and the cheese inside is melted. Let cool for 1 to 2 minutes, then slice and serve with more hot sauce, salsa, guacamole, and/or sour cream, if you like.