Preheat your oven to 300°F (150°C) and position four ramekins in a deep baking pan.

In a medium saucepan, combine 2 cups of heavy cream, 1/4 cup of granulated sugar, and a pinch of kosher salt over medium-low heat, stirring until the sugar dissolves.

Whisk the 5 large egg yolks until pale and thick, then gradually add the warm cream mixture while whisking continually.

Add 2 tablespoons of instant espresso powder and 2 tablespoons of Kahlúa, stir gently, and strain the mixture through a fine-mesh sieve.

Divide the custard into ramekins, then place in the oven with hot water halfway up the sides. Bake for 25-35 minutes.

After baking, cool on a wire rack for 4 hours, then refrigerate for at least 2 hours.

Before serving, sprinkle 1 tablespoon of granulated sugar over each custard and caramelize with a kitchen torch.