Preheat your oven to 300°F (150°C) and set out 5 heatproof glass jars or ceramic ramekins.

In a small, deep saucepan, combine the sugar and 1 ½ tablespoons of water. Cook over medium-low heat without stirring (swirl the pan instead) until the syrup dissolves and turns a deep, dark amber color.

Remove the pan from the heat and very carefully pour in the 2 tablespoons of hot water to stop the cooking. Watch out for hot steam! Stir quickly to combine.

Immediately divide the caramel evenly among the 5 jars (approx. 2 teaspoons each). Swirl each jar gently to coat the bottom, then set aside.

In a medium saucepan, combine the whole milk and heavy cream. Slice the vanilla bean lengthwise, scrape out the seeds, and add both the seeds and empty pod into the milk. Heat over medium-low until it reaches roughly 140°F (60°C) / steaming.

While the milk warms, lightly whisk the 4 egg yolks and ⅓ cup of sugar together in a large mixing bowl until smooth.

Gradually pour the warm milk into the egg mixture in a slow, steady stream while whisking constantly to avoid scrambling the eggs.

Strain the liquid through a fine-mesh sieve into a clean pitcher to remove the vanilla pod and any solids, then scoop off any bubbles or foam from the surface.

Cover the entire baking dish tightly with aluminum foil and bake for 20 to 25 minutes. Puddings are done when the edges are set but the centers jiggle slightly like jelly.

Remove from the water bath and cool on a wire rack for 30 minutes. Transfer to the refrigerator and chill for a minimum of 2 hours (or overnight) before serving.