Adjust the oven rack to the top shelf. Bring a pot of salted water to a boil.
Heat the milk in a large frying pan over medium heat. Add the cheeses to the hot milk and start melting. With a wooden spoon, stir gently but continuously, until all the cheeses are melted together.
Bring a pot of salted water to a boil and cook your pasta according to the directions on the box, and, as always, to make sure you achieve a proper "al dente" texture, drain it about 2 minutes before what is indicated.
Toss the penne and the cheese sauce together, season with salt and a generous amount of ground black pepper. Divide the penne between ten 6-ounce ramekins. Top with a light sprinkling of breadcrumbs and a grating of Parmesan.
Turn the grill on high and broil until golden and crisp on top, 3 to 5 minutes.
This recipe makes 10 kid-sized servings or 4 to 6 main servings.