Preheat the oven to 325°F(165°C).
In a small saucepan, heat the heavy cream and milk just until it starts to steam. Remove from heat and whisk in the brown sugar, cinnamon, ginger, allspice, and nutmeg. Set aside.
In a bowl, whisk together the egg yolks, pumpkin puree, vanilla extract and molasses.
Pour the cream mixture into the bowl and whisk to combine.
Pour this mixture through a strainer into a glass measuring cup. Then pour the strained mixture into 6 small oven-safe baking dishes (like 4 ounce mason jars or ramekins).
Set the baking dishes into a larger baking dish large enough to hold them all.
Pour hot water into a baking dish so that that water reaches halfway up the smaller baking dishes.
Bake for 35-40 minutes or until almost set in the center. They should still be slightly jiggly in the center.
Remove from the oven and cool on a wire rack. Then refrigerate until completely chilled, at least 2 hours.
For the whipped cream, you can use canned whipped cream, or make your own. Pour whipping cream and powdered sugar into the bowl of a stand mixer. Beat on medium until stiff peaks form.
Top the desserts with whipped cream before serving.