Cake flour is also called soft or weak flour. It contains 7-9% protein which is perfect for cakes cause it is sleek and smooth. While AP (all purpose) flour or pastry flour has 10-11% protein and more compacted and denser.
I would highly recommend that one should stick with whatever type of flour the recipe calls for. If it's AP flour, use AP flour, if bread flour, use bread flour to avoid messing up with the recipe itself. Yes it happens, some time.
But if you're really in a hurry, you need not to bug anyone cause not no way, not no how, here's an easy tutorial on how to make cake flour in no time right inside your house.