Cover the mold with a bit of wax paper and let it set in a safe place.
It is probably not necessary (with this recipe at least) to insulate the mold like you normally would. Most pumpkin fragrance oils contain at least a little cinnamon and/or clove essential oil in them, which will really get the saponification process going. This batch of soap will get HOT. Don't worry, this is normal. Also, don't worry about how dark the soap is getting. This is just part of the gel process. The soap will lighten back up as it cools.

