07/24/2011 at 02:00 PM EDT
Fresh from her split with husband
Marc Anthony, Jennifer Lopez
, who turns 42 on Sunday, is living it up in Miami to celebrate her birthday.
On Saturday night, Lopez and her entourage of 16 – which included her mother, sister, manager and stylist – enjoyed a lavish dinner at Scott Conant's restaurant, Scarpetta, inside the Fontainebleau hotel.
With a view of the ocean, the group indulged in a menu of authentic Italian dishes, including spaghetti with tomato and basil, foie gras ravioli and polenta.
"Jennifer looked radiant in a purple and silver evening dress," a source tells PEOPLE. "And when they brought out her birthday cake after the meal, she began to sing. She was very happy. The whole group had a blast, staying for hours. They closed down the restaurant."
Earlier in the day, Lopez worked up an appetite with a shopping spree, visiting the high-end boutiques at Bal Harbour Shops just north of South Beach. She bought several baby outfits for her 3-year-old twins, Emme and Max, at Bonpoint of Paris, and shopped at Hermes, Dolce & Gabbana, Valentino and Pucci.
On Friday night, after swimming in her condo pool with friends and family, including little Emme, Lopez and seven others enjoyed a pre-birthday dinner at the Wine Cellar of the Forge on Miami Beach, a favorite spot where she has dined with Anthony.
"Jennifer and her group arrived around 9 p.m. and went directly to the private wine cellar for a pre-birthday dinner," a source tells PEOPLE. "It was very secluded and beautiful among the bottles with bold and vibrant labels. The meal was served on a long rectangle mirrored table with cloud-like chandeliers hanging above."
According to the source, Lopez, who wore a long, brightly colored geometric patterned dress, was in great spirits. "She was chatty and charming," the source says.
For a surprise, the Forge's pastry chef created a special chocolate soufflé. It was presented to Lopez shortly after their meal, which started with appetizers of lobster peanut butter and jelly, a Forge specialty.
"Jennifer absolutely loved it," the source tells PEOPLE. "When the waiters brought the soufflé, they sang 'Happy Birthday' to her while pouring everyone a crystal goblet of champagne."