Birthday Cake As A Handbag How Can I Make A Deep Sponge Cake 9inch To Cut In Half As Am Making A Birthday Cake.?

How can I make a deep sponge cake 9inch to cut in half as am making a birthday cake.? - birthday cake as a handbag

As I had the sandwich cake tins decorated with myself, are too small (7inch), so I have) a deep box (hinges of 9inches can I do? Do you have a recipe for what will halve sufficantly, then cream together ..? Thanks