Everything I make that is "Italian" is typically from scratch. Thats how my grandmother made it, and there is no substitute.
I even crushed my own homegrown tomatoes, and have had the pot simmering for a while cooking them.
Gnucchis are of the sweet potato variety... which were hell to make, but I did that sunday while watching TV. Took a few hours, but in the end I have enough for some every week for a couple months.