01 - Preheat your oven to 350°F. Lightly grease a 2-quart baking dish or six 6-oz ramekins with butter or cooking spray.
02 - In a large mixing bowl, whisk together the pumpkin puree, whole milk, eggs, heavy cream, brown sugar, granulated sugar, and vanilla extract until completely smooth and no lumps remain.
03 - Sprinkle in the pumpkin pie spice, cinnamon, and salt. Whisk vigorously until all spices are fully incorporated and the mixture is uniform in color.
04 - Transfer the mixture to the prepared baking dish or divide evenly among the ramekins, filling each about three-quarters full.
05 - Place the baking dish or ramekins in a larger roasting pan. Carefully pour hot water into the roasting pan until it reaches halfway up the sides of the pudding container.
06 - Bake for 40 to 45 minutes. The pudding is done when the edges are firm but the center still has a slight wobble when gently shaken.
07 - Remove from the oven and carefully lift the dish out of the water bath. Let cool for at least 15 minutes before serving warm, or refrigerate for at least 2 hours to serve chilled.