Preheat your oven to 325°F (160°C).
Gently warm the first 1 cup of heavy cream and 1/2 cup of whole milk in a small saucepan until just steaming. Take it off the heat.
Whisk in the 1/2 cup of brown sugar and all the fragrant spices (cinnamon, ginger, allspice, cardamom, nutmeg) until dissolved. Set this lovely mixture aside to cool slightly.
In a separate bowl, whisk together the 4 large egg yolks, 3/4 cup of pumpkin puree, 1 tsp of vanilla paste, and 1 Tbsp of molasses until smooth.
Slowly whisk the slightly cooled cream mixture into the pumpkin-egg mixture until everything is beautifully combined.
For a super silky texture, carefully pour the mixture through a fine-mesh strainer into a clean container, pressing with the back of a spoon to get every drop through. This step makes your pot de crème wonderfully smooth!
Divide the mixture evenly into 5-6 small oven-safe ramekins or containers.
Place these filled ramekins into a larger baking dish. Carefully pour hot water into the baking dish, letting it come halfway up the sides of your smaller containers. This creates a gentle water bath.
Bake for 35-40 minutes, or until the edges are set but the centers still have a delicate wobble.
Remove the ramekins from the water bath, let them cool on a wire rack, then chill thoroughly in the refrigerator for at least 4 hours, or ideally, overnight.
Optional Topping: For an extra touch of indulgence, whip the remaining 1/2 cup of heavy cream with maple syrup and maple extract until it's light and fluffy. Serve a dollop on top of your chilled pumpkin pots!