PREHEAT oven to 325F. Arrange 8 ramekins in a baking dish (or roasting pan) large enough to hold all. Boil a kettle of water. Heat cream and milk in a saucepan set over medium, until it starts to simmer, about 5 min. Remove from heat.
WHISK pumpkin with 1/2 cup granulated and 1/2 cup brown sugar, yolks, vanilla, pie spice and salt in a bowl until smooth. While whisking, gradually add hot cream mixture. Pour into ramekins. Pour boiled water into baking dish until it comes halfway up the ramekins.
BAKE in centre of oven until custard is set but centre is still slightly jiggly, 35 to 38 min. Transfer dishes to a wire rack and cool for 10 min. Refrigerate, uncovered, until chilled, at least 6 hours.
SPRINKLE 2 tsp sugar evenly over each custard. Caramelize sugar with a kitchen torch until melted and golden.