Preheat oven to 350°.
In large bowl or measuring cup, whisk egg yolks and sugar until thickened and lighter in color, 2-3 minutes. Add pumpkin puree, spices, vanilla, and heavy cream and whisk until smooth.
Place ramekins in larger roasting pan and fill each with custard mixture. Pull out middle rack of oven and place pan on rack, remove one ramekin, and pour hot tap water until it comes halfway up the sides of the ramekins. Replace ramekin, cover pan loosely with foil, and carefully push rack back into place.
Bake for about 50 minutes. Lift up the foil and with a pot holder in your hand, very gently wiggle the pan. If only the center jiggles slightly, the custards are done and can be removed from the oven. If the entire custard jiggles, they're not done. Replace foil and bake for another 10 minutes. Check for jiggling again. Continue this in 10-minute intervals until fully baked and only slightly jiggling in center.
Remove pan from oven and remove ramekins from water (a pair of tongs will help). Place ramekins on wire rack to cool for about 10 minutes. Place ramekins in refrigerator, uncovered, and chill for at least 4 hours.
When ready to serve, sprinkle sugar over tops of custards and caramelize sugar using small kitchen torch. Alternatively, you may put the custards under the broiler for just a minute or two, but check after 1 minute so they don't burn.
Once bruleed, they must be eaten within an hour or sugar will liquify.