Preheat oven to 350 degrees F (175 degrees C). Spray a 9x13-inch baking dish with cooking spray.
Bring a large pot of lightly salted water to a boil. Cook elbow macaroni in the boiling water, stirring occasionally, until cooked through but firm to the bite, 8 minutes; drain.
Reserve 1/2 cup shredded mild Cheddar cheese for later use
Mix mild Cheddar cheese, sharp Cheddar cheese, sour cream, cottage cheese, and egg together in a bowl; season with salt and pepper. Stir cooked macaroni into cheese mixture. Pour macaroni mixture evenly into the prepared baking dish; sprinkle with the reserved 1/2 cup Cheddar cheese.
Bake in the preheated oven until cheese is melted and bubbling, 40 minutes. Let cool for 10 minutes before serving.
recipepes.comBaked Mac and Cheese with Sour Cream and Cottage Cheese, recipePT15MPT1H5455 calories