Need name of restaurant in Castellina on the square right next to the church. Best spaghetti and sauce we ever had need recipe. Seating between square and church
Have you thought of googling for 'restaurants castellina in chianti'? Quite a few have their own websites and are shown on googlemaps. From the map and the website photos you should be able to determine which restaurant you went to.
It may well have been Pizzeria Tre Ponte:
However, I doubt very much that any restaurant anywhere will give you their own recipe.
It is called "antica trattoria La Torre" (the tower), check the picture in my Castellina in Chianti page.
And here's that restaurant's website, in case its photos ring any bells: