Beware, Ice cream and cakes are Low GI foods because they are plenty of fats. I think ideally would be better to have a post shake without fat and fibers but with high GI carb and proteins(to rise insulin) immediately after workout and have a complete mixed meal(complex carb,prot,EFA,and fibers) 1,5-2 hours later to ensure a stable(and thus not high) glycemia.