Preheat your oven to 150°C (300°F). Arrange six 150ml (approx. 5-6 oz) ramekins in a large baking dish with high sides. The dish should be deep enough to hold the ramekins and allow for a water bath.

Prepare the vanilla bean: Split the vanilla bean lengthwise with a sharp knife. Use the back of the knife to scrape out the tiny seeds from both halves. Set aside.

In a medium saucepan, combine the heavy cream (750ml / 3 cups) with the scraped vanilla bean seeds and the scraped vanilla bean pod. Heat the cream over medium-low heat until it just begins to simmer around the edges. Do not let it boil. Remove from heat, cover the saucepan, and let it steep for 15-20 minutes to infuse the vanilla flavor.

In a separate medium bowl, whisk together the egg yolks (6 large) and granulated sugar (150g / 3/4 cup) until the mixture is pale yellow and slightly thickened. Be careful not to over-whisk, as this can incorporate too much air, which can lead to an undesirable texture.

Remove the vanilla bean pod from the steeped cream. Slowly and gradually temper the egg yolk mixture by whisking about half of the warm cream into the egg yolks. This process gently raises the temperature of the yolks, preventing them from scrambling. Once combined, pour the tempered yolk mixture back into the saucepan with the remaining cream. Whisk constantly until fully incorporated. If using vanilla extract, stir it in now.

Strain the custard mixture through a fine-mesh sieve into a pitcher or a large measuring cup with a spout. This removes any potential cooked egg bits or vanilla pod fragments, ensuring a silky smooth texture. Discard any solids caught in the sieve.

Carefully pour the strained custard evenly into the prepared ramekins, filling each one almost to the brim. Aim for approximately 125ml (4-5 oz) of custard per ramekin.

Create the water bath: Carefully pour the hot water (500ml / 2 cups) into the baking dish, surrounding the ramekins. The water should come about halfway up the sides of the ramekins. Be careful not to splash water into the custards.

Carefully transfer the baking dish with the ramekins and water bath to the preheated oven. Bake for 30-40 minutes, or until the custards are set but still slightly jiggly in the center. They should not be liquid, but they will continue to set as they cool.

Once baked, carefully remove the baking dish from the oven. Let the ramekins cool in the water bath for about 15-20 minutes before carefully removing them from the water. Place the ramekins on a wire rack to cool completely to room temperature.

Once cooled, cover each ramekin tightly with plastic wrap, ensuring the wrap doesn't touch the surface of the custard to prevent a skin from forming. Refrigerate for at least 4 hours, or preferably overnight, until thoroughly chilled and firm.

Just before serving, remove the chilled custards from the refrigerator. Blot any condensation from the surface of the custard with a paper towel. Sprinkle about 1 tablespoon (approx. 15g) of granulated sugar evenly over the surface of each custard. Ensure the sugar forms a uniform layer.

Using a kitchen torch, carefully caramelize the sugar. Hold the torch a few inches away from the surface and move it continuously in a circular motion until the sugar melts, bubbles, and turns a deep amber color. Be patient and ensure the entire surface is caramelized.

Let the caramelized sugar harden for 1-2 minutes before serving. The crème brûlée is best enjoyed immediately after the sugar has been caramelized, allowing for the delightful contrast between the warm, crisp topping and the cool, creamy custard.