My husbands little sister has just got engaged and having a party start of September, I have been asked to make a cake and have offered to do this as my gift to them. The problem is what they have since requested is a it complicated and can't quite get my head around I'm going to do it at this stage. So what I have been asked for is:

100 servings. Bride only likes plain vanilla sponge covered in fondant, no cream or filling etc. Groom only likes chocolate fudge cake with chocolate fudge (not White chocolate) covering and no fondant. Their only other request is that cake is White and then I have free rein on design etc. At the moment I am completely stumped. The only thing I can think of is the stunning half White half chocolate wedding cake in the gallery but that is way beyond my skill level. Any suggestions? I am thinking I may have to do two separate cakes but in the mean time I have emailed them back to say it's not possible for me to make brown chocolate look the same as White fondant.

Sil is a newly qualified florist so before I got this request I had been getting excited about doing a variation of Peggy porschen Rose tower cake as I'm very confident in my roses.

Any suggestions would be welcome?!

Maybe I'm not reading this correctly, but she likes vanilla sponge cake (with NO filling? Not even buttercream?) with a fondant cover and he likes chocolate cake with chocolate buttercream....no fondant, but they BOTH requested a white cake?
Huh? not quite getting it here.

Can't you smooth the chocolate buttercream to look like fondant? That would give the groom what he wants and still tie in with the smooth fondant look.

Just do a tiered cake. Maybe 4 tiers with alternating choc buttercream / white fondant cakes. Perhaps stack your cakes so you can place the roses you love to do (white--or maybe a color) between the tiers, or have them cascading down the sides of a regular stacked cake.
Just a thought!

Yes, sounds like you may have to make two separate cakes.

"Maybe I'm not reading this correctly, but she likes vanilla sponge cake (with NO filling? Not even buttercream?) with a fondant cover and he likes chocolate cake with chocolate buttercream....no fondant, but they BOTH requested a white cake?
Huh? not quite getting it here. "

exactly I'm not quite getting it either! I have sent them an email to try to clarify but I think they genuinely think I can colour brown chocolate however they want! This maybe my fault tbh because I did a giant cupcake for her bday few months back and I did say I could do the choc case pretty much any colour she wants (ie candy melts). Hmmm I'm hoping I'm getting the wrong end of the stick here because it's becoming more complicated then I had originally planned......and to think she has also asked me to do the wedding cake next sept but luckily she wants cupcakes for that so should be easier to accommodate.

I do like the idea of stacked alternating tiers though thank you

First, you need clarification, then I too believe you need to do two stacked cakes. One for the bride and one for the groom. Maybe you could make two gift cakes with edible ribbons.

I would do the alternating tiers of white and chocolate. Cover the white cake in white chocolate ganache and then white fondant. Frost the chocolate cake in a nice chocolate fudge and ganache and then cover it with white fondant. He can peel the fondant off. She can't scrape frosting off as easily. The white chocolate ganache will become part of the fondant covering.

Then, you get a beautiful white cake to decorate with all of the roses you planned.