I've only made one pumpkin brew and that was about 2 years ago. We used canned pumpkin and we baked it first and added it to the boil. Then we added a few shots of rum to the secondary. It turned out wonderful and people are still asking for a repeat, only I don't like to repeat brews. There's prolly a million ways to do what you want, that's the beauty of brewing. I know that doesn't really answer your question but don't be afraid to try anything when it comes to brewing. Find an idea like you just did and then look up the different ways to make it and then just try one. From there you can figure out what you need to do different next time (more pumpkin, add it to primary, add it to mash or whatever you desire). Cheers!