I made a pumpkin beer with an extract/specialty grain recipe two years ago. You're on the right track by baking the pumpkins. Do that a day or so before you want to brew, then chill the pumpkin cubes in the fridge. Now, I boiled the pumpkin chunks in the wort, and the beer was pretty good. I've read other places that you should only steep the pumpkin chunks for 45 minutes to an hour at @ 155F then remove the chunks before boiling the rest of your ingredients. When I brew a pumpkin ale again, this is how I will do it to compare which I like best. Be sure to use SUGAR PUMPKINS, not just halloween carving pumpkins!!! That is very important. Sugar pumpkins are for cooking, eating, baking, brewing. Good Luck!