Bring a large pot of salted water to a boil over medium-high heat and cook noodles until al dente, about 12 minutes or according to directions on the box. Drain and reserve for later. Preheat oven to 500 degrees F.
In a large pot set over medium heat, melt butter. Add flour and whisk to combine, stirring occasionally, for about two minutes or until golden. Whisk in milk, then increase heat to high, whisking constantly as the mixture thickens and comes to a simmer. Reduce heat back to medium, add salt and American cheese. Whisk for about a minute, until American cheese is fully melted, then add Jack cheese, whisking for an additional two minutes until the sauce is smooth and velvety. Add noodles directly to the sauce, and stir with a wooden spoon for about two minutes or until the noodles have soaked up some of the sauce. Stir in the pickled jalapeños, and transfer the mac to a baking dish.
Add Cheetos to a food processor and pulse until finely ground. Sprinkle the Cheetos dust evenly over the macaroni and cheese, and bake for 10 minutes, until the crust is fragrant and browned. Let cool, then serve.