Zac gets saucy

The folks at Bertolli — that’s right, the spaghetti sauce people — transformed a garden courtyard at Lincoln Center into a cozy ristorante (mmm, that lamb shank) for a party hosted by Zac Posen and celeb chef Rocco di Spirito after Zac’s Z Spoke show Saturday night.  Zac pals attended — Michelle Trachtenberg, Rashida Jones and Emmy winner Claire Danes (looking lovely, but so stand-offish).  Trachtenberg was friendlier.  “I love to cook,” she said enthusiastically, when asked if her creative talents (acting and style-wise) translate to the kitchen.  “I’ve never been to Italy,” she said, but she’s dying to get there.  “I have to go when I can take at least a week off after …to depuffify.”