In a medium saucepan, stir together the brown sugar and cream. Bring it to a boil, stirring often and let it boil until it thickens, about 5 minutes.

While that boils, whisk the egg yolks, whole egg, cornstarch and vanilla in a large glass measuring cup.

When the caramel is thickened to the consistency of corn syrup, remove it from the heat and add the butter and Scotch.

Put the pot back on the heat and melt the butter. When that has melted, stir in the milk and heat until the milk starts to steam.

Very slowly, starting with dribbles, whisk the hot milk and caramel into the eggs and corn starch. When it is all incorporated, pour it all back into the pot.

Over a medium low heat, whisk constantly until thick. It is thick enough when the whisk leaves a trail that stays for several seconds. Do not let it boil.*

Pour the pudding into a heatproof bowl through a fine-mesh seive and cover with plastic wrap directly on the pudding.

Chill for at least 4 hours before serving. Garnish with a dollop of whipped cream or shaved white chocolate.