Hello all and thank you SO MUCH, in advance. 

I am new to baking - as in baking & cake decorating are something that I've wanted to explore for a while now and this is really my first forray - but we all have to start somewhere, right?

Anyway, it's my Mother's birthday so I thought I'd bake her a cake as she's very difficult to shop for, but as it turns out she's been craving a marzipan cake. I'm pretty sure she means one covered/frosted with marzipan (I have vague memories of having this at a local bakery as a child?) but am not sure. I originally had in mind a simpler layer cake with raspberry or cream filling or both but I don't know much about marzipan so I'm in need of advice on cake type, fillings, flavors & other frosting. I've seen recipes for marzipan (almond flavored) cake that sounds denser than more traditional sponge type cake, but would that be a really heavy cake with the marzipan topping? Would traditional cake hold up to/ pair well with the marzipan? Also, it sounds like I need a crumb layer first, but I also see recipes for marzipan with chocolate ganache, for example. Does anyone ever frost over marzipan? I'm a little lost with the marzipan, as you can see!

Sorry for the long post and thank you for any thoughts or advice! 

(I am cheating and getting the marzipan itself from a local bakery.)

1st off I'm no one has been able to help you.  I know little about marzipan but I'll share what I know/think :)

It sounds like the marzpian you are  you are getting will be like a fondant type icing.  From what little I know about marzipan it is basically ground almonds, &  (powdered?)sugar so it would be an off white - almost tan dough like icing.  A crumb coat can be done w/ganache or b'cream.  I use b'cream.....and though I have never done it I would guess one could easily 'frost over' marzipan - expecially if you mean decorating on it.   Yes, a 'traditional' cake should easily hold up under it.

As kakeladi said, marzipan is much like a more tasty fondant.  In the UK, it is traditionally used for covering fruit cakes, but they also use it in lots of other ways.  Yes, you can put it on any type cake and yes, you do need at least a crumb coat under it and yes, you can frost over the top of it.  It is really just another layer of flavor.  Why not ask your mom what type cake she is craving and try to replicate it.