Mmmh that's a great question !

Callie would be a birthday cake, the kind that's filled with sprinkles and taste super nostalgic. You know it's gonna be good but it's always a nice surprise.
Marie is a Forêt noire. A very heavy cake that's super chocolatey and extremely sweet. It can be overwhelming to some. But the ones that enjoy this cake REALLY enjoy it.

Marina would be an ice cream cake, as a reference to cake vs ice cream. I think she'd enjoy the flavor and texture a lot more than any other cake.
Pearl would be a fraisier. Very elegant and delicate, a little bit complex to make but a delight to have.

Shiver would be a carrot cake. When you overlook it without tasting it, you immediately judge it and think it must suck. But people that took the time to taste it know it's a genuinely great cake.
Frye would be a little bit too out of the box for a cake, so I'd imagine her as a crookie (croissant-cookie mix). She likes wild mixes in food and I think there's a beauty in that sort of thing.
Big Man would be a chocolate mug cake. The kind of thing you do at 2 AM because you're barely awake but need the comfort of a warm cake. Some call it simplistic but to say the truth, it's one of the most comforting things ever.