WoWDB

The Noblegarden Chocolates required for this achievement are collected from Brightly Colored Eggs that are found during Noblegarden around each race's second town (first proper town after starting area):  Azure Watch, Bloodhoof Village, Brill, Dolanaar, Fairbreeze Village, Goldshire, Kharanos, and Razor Hill.

If you keep eating after the 25 needed to earn Chocolate Lover, you can also pick up the achievement Chocoholic after 100 total chocolates. 

These Noblegarden Chocolates (pre-eaten only, unfortunately) can also be used to purchase various rewards like Swift Springstrider, Spring Rabbit's Foot, Tome of Polymorph: Rabbit and various outfits from Noblegarden Vendors.