There are two powdered spices in this recipe, the turmeric and asafetida (and ginger if you use it), and it's okay to use those as they are. Some of the other spices in this blend are also likely already in your kitchen in powder form, like pepper, cumin, coriander and cayenne and if you're wondering if you can substitute those for the whole spices, I'd advise against it. That's because powdered spices have usually lost a good part of their flavor and fragrance, especially cumin and coriander. The spices in this blend also need to be roasted beforehand, so you'd be much better off using whole spices.