For pudding, in medium saucepan over medium heat, whisk nondairy milk, pumpkin, chocolate, arrowroot or tapioca flour, sugar, cinnamon, and salt. Whisk constantly until chocolate is melted, about 5 minutes. Continue to whisk for 8 to 10 minutes, until mixture begins to thicken and large bubbles start to pop on top. Once thick and bubbling, continue to whisk for 1 to 2 minutes longer. Strain through fine sieve into large bowl. Stir in vanilla. Cover and cool to room temperature (do not refrigerate until poured into the crust).