Courtesy Anna Hightower. Inset:Evan Agostini/Invis

Cowabunga, Dude! Jennifer Hudson and David Otunga wanted to give their son, David, a birthday to remember. So they gave him a party that would make any other 5-year-old boy turn green with envy.

First up on August 10: a visit to the Nickelodeon Suites Resort where they mingled with Spongebob Squarepants, Squidward and other Nickelodeon characters. “Not sure who was more starstruck, him or Mommy & Daddy” Otunga posted on Instagram.

The family then posed a meet and greet with all four Teenage Mutant Ninja Turtles. It had been a special weekend at the Nick Hotel; they had broken the Guinness World Record by having 1,394 people dressed like the Ninja Turtles simultaneously. “Obviously, Little David was in heaven,” says a source. “But you could tell that Jennifer and David were having a fantastic time.”

And then, the crowning achievement: a Ninja Turtle Cake.

Courtesy Anna Hightower

Hudson’s team had been unimpressed with another baker’s version of the Ninja Turtles, so they turned to Anna Cakes, the bakery who also made Chris Kirkpatrick’s wedding cake. After a frantic brainstorming session, “I sent over some sketches,” Anna Hightower, owner of Anna Cakes, tells PEOPLE, “and we delivered the cake the next day.” Hudson was delighted with the cake, and posed for pictures with it.

Courtesy Anna Hightower

The Oscar winner and her family topped off the night by playing “Family Double Dare” — and yes, they got slimed. “Everyone was laughing,” says an onlooker. “Jennifer was so excited to be slimed; she couldn’t stop laughing after it happened. I don’t know who had more fun during the birthday: Little David or his parents!”

—Steve Helling