Prepare the caramel: In a saucepan, melt the sugar over medium heat, stirring occasionally, until it turns golden brown. Be careful not to burn it.

Once melted, slowly add 100 ml of milk while stirring continuously. The mixture may bubble, so stir until smooth. Set aside.

Prepare the pudding: In a separate saucepan, combine the remaining milk, sugar, cornstarch, and salt. Gradually whisk until smooth.

Place the saucepan over medium heat and cook, stirring constantly, until the mixture thickens and starts to bubble.

Temper the egg yolk by adding a few spoonfuls of the hot mixture to the yolk while whisking, then pour it back into the saucepan.

Cook for an additional 2 minutes, stirring continuously.

Remove from heat, stir in the vanilla extract, and mix in the caramel sauce.

Pour the pudding into individual serving bowls or glasses.

Cover the surface with plastic wrap to prevent a skin from forming.

Chill in the refrigerator for at least 2 hours before serving.