Uh...look at the scene where Jennifer Garner sticks her torso out of the stretch limosine. If that's not a Big reference, I don't know what is!
Big was a bodyswap comedy, this is a bodyswap comedy. A young person wishes they could escape the confines of youth and wakes up, trapped in a older person's body, forced to deal with the problems of love and a career. Said character learns maturity as the film progresses but comes to miss their lost youth. Inevitably, they get their wish and return to their previous age.
I've just described the plot to 13 Going on 30. And, whaddya know?, Big too.
There's your connection.
Incidentally, the 'will-they, wont- they' aspect of 13 Going on 30 is completely redundant since there's no doubt Jennifer Garner's character will return to 13. After all, it's unusal for our protagonist's happy ending to consist of losing 17 years of her life. We therefore know that she'll have a second chance with Mark Ruffalo's character, regardless of whether she screws it up as a 30 year old.
Whoops, maybe I'm thinking about this sort of lightweight fluff too much. All I know is, Big was a lot more heartfelt.