Four Peaks Brewing Company: Double Pumpkin Porter

Official description from the brewery:
It's not enough that we make the most popular and best-selling seasonal beer in Arizona, Pumpkin Porter; it seems the people always want something more. Something ... bigger. So in 2014, we heard their cries and created Double Pumpkin, an imperial Pumpkin Porter. We increased the spices. We upped the maltiness. We boosted the body. And in the end, we created what we think is a sublime (and flavorful) evolution of Arizona's best fall seasonal. But fair warning; despite Double Pumpkin's size, it's only around for a limited time each year.