Dolci Peccati bills itself as the "sweetest truck on the road," and that's true in every sense of the word. Not only was it one of the first all-dessert trucks to hit the road in Miami, but also its 20-something twin co-owners are among the friendliest mobile proprietors around. The Yepes sisters are all smiles in Hello Kitty aprons as they serve small but satisfying portions of the creamy gelato they make in modest batches every day. Every flavor is creamy and dense, as gelato should be, with the underlying boldness of component ingredients. Mint-chocolate chip, for instance, explodes with spearmint flavor, while cookies and cream melts with a rich vanilla finish. Of course, there are all the usual gelato flavors, such as pistachio and hazelnut, but the sisters whip up new combinations, like chocolate-blood orange, to mark special occasions or simple changes in whimsy. Meanwhile, their signature garnish is a special sweet-savory balsamic sauce most popular over strawberry and other fruit flavors.A small, approximately three-quarter-cup serving ($3) packs a lot of flavor, so it's almost guilt-free, although a large ($4.50) won't set you up to go for caloric broke either. Larger take-out containers are available for $8 and up, but you'll want to hurry home with those — the frozen goodness, like so many other amazing things in life, doesn't hold up well over time.