In a medium bowl, whisk pumpkin puree until loosened. Slowly pour in 1 cup whole milk and 1/2 cup heavy cream, while still continuing to whisk the pumpkin puree slowly. Whisk in 2 large eggs, 2 teaspoons pure vanilla extract, 1/2 teaspoon ground cinnamon, and 1/2 teaspoon kosher salt until all the ingredients are combined and the mixture is a thick but still fluid, mottled pale orange.