Preheat oven to 325 degrees F.
In a medium bowl, whisk together the sugar and egg yolks until they turn a pale yellow and begin to form ribbons. Set aside.
In a medium saucepan, add the cream, milk, pumpkin puree, maple syrup, pumpkin pie spice, cinnamon and salt. Turn the heat to medium and whisk until all the ingredients (almost) merry together and it’s hot to the touch. Next, we’re going to temper. Add about 1/4 cup (you can eye ball this) of the hot cream and pumpkin mixture to the bowl with the egg yolks; mix. Repeat this entire process a few times until the egg yolks are warm. Pour everything back into the saucepan and turn the heat to medium. Stick a thermometer in the milk mixture and heat until it reads 175 degrees F and is thick and coats the back of a spoon.
Set ramekins inside a baking dish. (Note: You also may need more than one baking dish - I didn’t have one big enough to house all of the ramekins.) Pour the custard through a fine-mesh sieve into a large 4-cup measuring cup and then divide the custard amongst ramekins.
Transfer the baking dish(es) to the oven and then add the water to the baking dish (I found it easiest to use a tea kettle) until it reaches about 1 inch up the sides of the ramekins. Bake for about 35 minutes, until the center of the custard is firm and a knife inserted comes out clean. Transfer custards to a rack to cool. Place in the fridge to chill, until cold, about 2 hours. Serve with whipped cream.