Special equipment: 12 (2-ounce) ceramic ramekins, a 2-ounce ladle, a brulee branding iron (see Cook's Note*) or blowtorch
Preheat the oven to 350 degrees F.
In a heavy bottomed pot bring cream just to the boil. Remove from heat, and add thyme and let sit for several minutes. Remove the thyme sprigs.
Meanwhile, whisk together the egg yolks and sugar in a separate bowl. Place the mixing bowl on top of a towel to keep it from wobbling while whisking in hot liquid. Gently whisk 1/3 of the hot cream mixture into the egg yolks, to temper the yolks and prevent lumps take care not to make an excessive amount of bubbles. While gently whisking, slowly pour the remainder of the hot cream mixture into the egg yolk mixture. With a spoon, skim off any bubbles that may have come to the surface.
Evenly space the ramekins on a paper towel-lined baking dish to prevent ramekins from sliding. Fill each ramekin to just below the top. Place on the extended middle rack of the oven. Carefully pour hot tap water into the baking dish until 3/4 of the way up the sides of the ramekins. Be careful not to get any water on the custard mixture. Cover the baking dish with aluminum foil and very gently slide it towards the center of the rack. Bake for about 30 minutes. Remove from the oven. Uncover and let the custards cool in the water bath until they are cool enough to handle. Remove. Chill in the refrigerator for at least 1 hour (see Cook's Note**).
Evenly top each custard with 1 to 1 1/2 teaspoons of sugar. Burn the sugar with a blowtorch or hot branding iron. It is important that the sugar layer is thick enough and goes all the way to the edge of the ramekin; any exposed custard can burn and curdle. Serve shortly after burning the sugar so that the burnt sugar doesn't soften.
*A brulee branding iron is a thick metal puck on the end of a long metal wand. It's heated by putting it on a metal surface such as a cast iron skillet over high heat. After heating for about 15 minutes, it's placed directly on the creme brulee sugar topping to create caramelization. It's necessary to reheat it for a few minutes between each creme brulee. **Custards can be made up to 1 day in advance and bruleed when served.