Get your left over cake and mashed it then set it aside. then add 1 cup of whip cream add cold water and whisk it at a very high speed till it turn fluppy then get any cup of choice I use disposable transparent cup and pour the mash cake inside then whip cream you can use piping bag or spoon anyone then you will add another mash cake and again whip cream that's all you can top it with chocolate or anything of your choice