Cook the spaghetti + olive oil according to package directions (minus a couple of minutes). You want it to be al dente. Drain spaghetti and place in a large bowl.
Melt the butter in a medium skillet. Add garlic and cook until sizzling and lightly browned, 1 to 2 minutes. Remove from heat; stir in sour cream, lemon zest and ⅓ cup lemon juice. Pour lemon sauce over the spaghetti and stir. Add Italian parsley and ½ cup Parmesan and stir some more. Pour lemony spaghetti in a greased 1.5 quart casserole dish.
Cover dish with foil and bake for 30 minutes. Take dish out of the oven and remove foil. Sprinkle ½ cup Parmesan on top. Drizzle juice from ½ lemon over the top of the pasta. Sprinkle pepper and salt on top. Place dish back into the oven for 7 or 8 minutes, just until cheese is melted and noodles have begun to turn golden in a few places. Serve immediately.
Notes
Serve pasta with lemon wedges, for those who like some extra tang in their pasta.
Try adding sliced mushrooms into the dish...sauté them with the butter and garlic.
Try adding cooked bacon. Everything is better with bacon!
This spaghetti is also great when served as a side dish to roasted chicken.
If you'd like the finished dish to turn out a little bit creamier just use less pasta.