2 cups heavy cream (or substitute half-and-half)
1 vanilla bean, split lengthwise
5 egg yolks
½ cup sugar, plus more for topping
Preheat oven to 325°F. In a saucepan over low heat, combine cream and vanilla bean and cook over low heat until just hot. Let steep for a few minutes, then discard vanilla bean. Meanwhile, in a separate pan, bring a few cups of water to a boil.
In a bowl, beat the egg yolks and sugar together until fluffy. Temper the egg mixture by stirring about a quarter of the hot cream into the egg mixture, then pour the egg mixture into the remaining cream—stirring constantly. Pour the custard into four (six-ounce) ramekins. Transfer the ramekins to a baking dish. Fill the baking dish with the boiling water halfway up the sides of the ramekins. Bake for about 30 minutes, or until the centers are barely set (somewhat jiggly in the center). Remove from the oven and let cool. Crème brûlée custards can be made a few days ahead until this point in the recipe. If making ahead, let cool completely, then wrap each ramekin in plastic wrap and refrigerate until ready to torch/broil.
When ready to serve, top each custard with a teaspoon of sugar and spread into a thin layer. Use a crème brûlée torch or the oven broiler to scorch the tops of the custards. With direct heat, the sugar will caramelize and harden on the surface. If using a broiler, preheat to high and position the ramekins about 2 to 3 inches from the broiler. Broil with the door ajar slightly and keeping a close eye on the custards until the sugar browns and blackens slightly, about 5 minutes. Serve within two hours of broiling.