baked ziti fast n easy

1 lb box ziti
1 onion chopped
1 lb ground beef what ever type u use lean or %
2 26oz of spaghetti sauce your choice
6 oz provolone sliced
6 oz mozzarella shredded
1 1/2 cups of sour cream
2 tbs of parmesan cheese
oven 350 cook pasta 8 mins from boil.....drain....in large skillet brown beef n onions over med heat add spaghetti sauce simmer for 15 mins .............9 x 13 sprayed baking dish...or buttered your choice... now in baking dish 1/2 of ziti .provolone.sour cream 1/2 of sauce mixture next remaining ziti mozzarella.and sauce mixture top with parmesan cheese bake 30 mins till cheese is melted..................enjoy