Creating food (Lava cake) in blender?

A little project i'm trying to do to maybe increase my confidence in cg again for the new year, little steps, i suppose! :)

My end goal is for an animation like this: https://giphy.com/gifs/coffee-time-4w3xNt1BpCYiQ   https://giphy.com/gifs/QGeOG1zgrXRte

Basically, I want to actually cut open the cake, and have the chocolate run out in it.

Currently i'm still creating the cake and struggling with that, sculpting it and texturing it. https://imgur.com/a/d6Tw6

right now i'm just trying to add a normal map, I don't know if it's working. and also, how would I create frosting, and the chocolate that'll be oozing out? How will I cut the cake?  How do I get the liquid simulator to be 'limitless' like real liquid so it won't be bounded by an invisible  box and will ooze randomly?  Thank you, adivce needed!