It is my daughters 18th on Friday and I am throwing her a party. I for some reason decide to cater single handedly for up to 150 guests and turned down the shop bought cake offered by her grandad and opted to make it myself.

I am making a lovely purple and silver cake with purple metallic lustre on it and silver coated choclate hearts. The cake inside will be a light sponge with buttercream.

My problem is what day to make it so that it is still fresh, but not so last minute I am doing that at the same time as decorating the venue and doing the rest of the food.

I bake a lot - a hell of a lot, but nothing I make stays around for long. So I am not sure how long this type of cake will stay fresh.

I am assuming the icing (fondant) will help to preserve it. Help please anyone.

Sponge cake should keep fresh for a week if you don't let air get to it.

Thanks.