A customer just requested a yellow cake filled with "you know that chocolate mousse filling that BJ's makes?" Well, I don't know that chocolate mousse filling that BJ's makes. Has anybody tried it? What's it like? Puddingy? Whipped ganache-y? Buttercreamy? Chocolatey whipped creamy? Any suggestions as to how I could replicate this (and not need refrigeration) would be so greatly appreciated! Thanks!

Well the BJ's by me has a pudding like filling that they call chocolate mousse. I'm in NY