Would this cake frosting work? Some cake advice needed please

[Theladyinthecardigan]

I have baked two round thin coffee cakes for Thurs when I need a birthday cake.

Thurs am I was planning a cheat frosting
before work... mix tub ready made vanilla buttercream, tub marcapone and some rum flavouring. Layer the sponge and add a layer on top. Cover top with grated chocolate. (Aiming for a tiramisu flavour)

Will that work or would marscapone and buttercream combined end up runny?

Is there a way of getting some chocolate flavour in there? Feel like it might be a bit bland.

Can I get away with doing the whole thing today and keeping in fridge until Thurs?

It might be slightly runny but if you add cocoa it will add both a chocolate flavour and help stiffen it up.

Two things. I think 4 days is too long to leave it in the fridge, sorry. And I’d probably make a chocolate ganache for the filling, then just use bought butter cream for the top-maybe with a bit of coffee flavouring in it. I’d probably freeze the cakes now, then decorate it on Wednesday evening.

It will need a fridge if it's half mascrapone. But it shouldn't be runny no. I make my frosting with half butter half mascrapone and IS and it's a good texture if refrigerated. But make sure the cakes are cold. Also some of the filling can kind of soak into the cakes so put more filling than you think you need.

I would probably not mix the buttercream and mascapone - add chocolate and icing sugar to the mascapone and do 2 layers of icing in the middle and one on top. Soft cream cheese would be an alternative to mascapone and very predictable.

Thanks for replies.

So if I freeze the sponges now, take them out weds pm, decorate thurs am.

Im not really a baker and I'm going to be quite short on time. Im picturing a messy kitchen at 8am and going to work frazzled.
Think Wendy Craig in Butterflies.

I'm following up your ganache/frosting suggestions thanks, googling for a foolproof recipe.