Position the rack in the center of the oven and preheat the oven to 350 degrees. Crumble the sausage meat into a large saucepan and brown over medium heat, stirring often, about 4 minutes.
Stir in the cooked pasta and half the cheese. Spread evenly into a 9-x13-inch baking pan. Top evenly with the remaining cheese.
Bake until the cheese has melted and the casserole is bubbling, about 20 minutes. Let stand 10 minutes at room temperature before slicing into 8 pieces.
Recipe from the kitchen of Weight Watchers. 8 Weight Watchers Points Plus Value per serving.