Step 1

Fill a medium bowl with ice water. Set a fine mesh sieve in another medium bowl; set the bowl in the ice water bath.

Step 2

In a small skillet, combine 1 1/2 tablespoons of the cream with the Scotch, brown sugar, water and salt and cook over moderate heat just until the sugar is dissolved. Let cool slightly.

Step 3

Put the egg yolks in a medium bowl. In a heavy, medium saucepan, bring the remaining 3 1/2 cups of cream to a simmer with the vanilla bean and seeds. Remove from the heat. Add the butterscotch chips to the hot cream and let stand until melted, 2 to 3 minutes. Whisk until smooth. Gradually add the hot butterscotch mixture to the egg yolks, whisking constantly.

Step 4

Return the mixture to the saucepan and cook over low heat, stirring constantly with a heatproof rubber spatula, until thick, about 15 minutes. Do not let it boil. Strain the pudding into the bowl in the ice bath and stir in the Scotch mixture.

Step 5

Pour the pudding into glasses and refrigerate until thoroughly set, at least 4 hours or overnight. Serve the pudding with whipped cream and caramel sauce.