BARBIE DOLL BIRTHDAY CAKE

[Tigerlion]

I want to make my DD a Barbie doll cake as I thought this would be relatively easy but am getting a bit confused. I have just made a Delia sponge mix which is cooking in the oven which I put in my 2 litre Pyrex bowl. However it only comes up to a third of the bowl's height. So, am I meant to triple all the ingredients (9 eggs etc)?

Also, I then intend to slice it in half, put some butter icing in, then put it together, stick Barbie in and then put butter icing all over the dress part. Is this how I am meant to do it or does anyone have an actual recipe/ instructions for doing it properly.

PLEASE HELP!!!!!

I made this cake with a Bratz doll for my dd's birthday this year. I did the pyrex bowl cake and then made up the rest of the height with ordinary roud cakes which I cut to the right shape and stuck togther with butter icing. hth

Sorry that should be round cakes