Thinking ahead, I made WAY more pasta and heated an whole jar of sauce, then put together Baked Spaghetti. I just found this pic online, since I didn't take a pic of my spaghetti. But it looks exactly these same, except that we don't have plain white plates.
This is one of the easiest recipes and does NOT taste like leftovers if you eat it a few days later.
I mixed together the leftover cooked spaghetti, about 1/2 jar of sauce, 2 cups of shredded mozarella cheese and a can of sliced mushrooms. Dumped it in a casserole dish, covered it and stuck it in the fridge. I have also frozen it in the past. A few nights later, I pulled it out, baked at 350 for about an hour, then added more shredded mozarella....yes, more....to the top. Stuck it back in the overn until it was nice and melty.
It was delish!!
If you want a specific recipe, there are a ton on line. But I like to just add what I have available. I have, in the past, added cottage cheese to the mixture an it kinda had a lasagna taste to it. Yummy!!