hi there. I'm making a wedding cake for mid October. I've been asked to make a 3 tier round cake. The base layer being a rocky road, the middle a carrot cake and the top a vanilla sponge. I'm ok on the two top tiers but the rocky road is causing me a bit of stress! ive worked out how i can make a big 14" rocky road with a smooth top. she wants it covered in sugarpaste. the thing is, ive never made such a big fridge cake. will it hold up to the rest of the cake? will it melt and go sloppy? ive worked out how to make it nice and smooth by setting a base of chocolate first, then doing the biscuit cake in the middle then finishing it off with more melted chocolate. do you think this is a good idea or a bad idea - be honest! i have suggested i make a chocolate cake and adding in marshmallows, sultanas and maybe maltesers or broken shortbread. - or not. dont know whether to leave out the biscuit. im in a real pickle as to which route to take for this. i think both methods have pros and cons and both could cause issues. i just mainly need a 'rocky road' type cake that will hold up for the day and look great covered in sugarpaste. any advice would ber very very appreciated. thanks in advance.

Have you considered covering it in chocolate ganache?

Please first of all ask the customer what they mean by "rocky road" This might mean a chocolate batter with the marshmallows, chips and nuts. OR it may mean some local variety that we don't know about.

You can certainly add stuff like chips, nuts, mini marshmallows to cake batter and the integrity of the cake will not be changed. There are "marshmallow" candy flavourings that can be added to cake batter to enhance the special taste.

Or you can make a "rocky road filling" with chocolate icing and the add-ins which will be tricky to spread but will set up just fine for handling.

But "fridge cake" in that size would be liable to break and you can tell the customer that upfront. I can see making it in 3-4 layers with a good solid ganache in between, but I would charge 4X for the trouble...