Chocolate chip cookies are the ultimate taste of home. The ingredients are usually findable no matter how remote the place I have lived. They have marked heartbreak and homesickness and celebration. I have used the recipe from the back of the Toll House chocolate chip package. (I still use one that I cut from a bag that was carried over oceans to the Sahel more than 20 years ago.) and the persnickety and delicious New York Times recipe using butter from France, chocolate from Tuscany and organic flour from Lazio. Pretty much all chocolate chip cookies are good chocolate chip cookies.
In Rome you can find chocolate chip cookies at a bar just off the Piazza Santa Maria de Trastevere and if you are really desperate at one of the many many Subway sandwich shops. I think that homemade chocolate chip cookies are best. Most groceries stores in Rome have brown sugar or you can use molasses from the health food store. Chop up a bar of 70% chocolate in place of uniform chips and make sure you have a baking tray that fits in your oven and you have everything you need.
I read some great articles about chocolate chip cookies over the Christmas holiday. The New Yorker blog explores the history behind the iconic treat and The Food Lab on Serious Eats dives deep into cooking geek science territory. Design Mom also has a very thorough post where she tests all kinds of ingredient and temperate variables. So you don't have to.