What spices taste umami?
As others have said, there are few spices with umami. However, if you're looking for something that you can use in the same way as a spice, then I suggest simply blitzing dried porcini (cep) mushrooms in a blender or grinder into a fine powder and using that. It has a deep umami flavour - try rubbing it on a steak before cooking and you'll be blown away.