Preheat oven to 350 degrees Fahrenheit. Next, prepare a water bath by filling a 9-inch by 13-inch baking dish half-way with water. Set the baking dish in the oven.
Whisk pumpkin purée, egg yolks, cream, sugar and spices together in a large mixing bowl until uniformly blended.
Strain the custard base through a fine-mesh sieve to remove any pulpy bits. And then, pour the custard base into 6 (6-oz) ramekins, and gently set them into the water bath. Bake until just set, about 40 to 50 minutes.
Cool to room temperature, and serve with whipped cream.