1Cook the elbow macaroni according to the package instructions. Drain and set aside.
In a medium saucepan, melt the butter over medium heat.
Add the flour to the melted butter and whisk continuously for about 2 minutes to form a roux.
Gradually add the milk to the roux, whisking constantly to avoid lumps. Continue to cook and whisk until the mixture thickens, about 5 minutes.
Add the shredded cheddar cheese to the sauce and stir until the cheese is completely melted and the sauce is smooth.
Season the cheese sauce with salt and black pepper.
Add the cooked macaroni to the cheese sauce and stir until the macaroni is well coated.
Transfer the mac and cheese to a serving dish and sprinkle the crushed Doritos on top.
Serve immediately and enjoy your Doritos Mac and Cheese!