Fill a medium bowl with ice water. Set a fine mesh sieve in another medium bowl; set the bowl in the ice water bath.
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.
Put the egg yolks in a medium bowl. Whisk well.
In a heavy, medium saucepan, bring the remaining 3 1/2 cups of cream to a simmer with the vanilla bean seeds. Remove from the heat. I've also used 1/2 teaspoon of vanilla extract in leu of the vanilla bean seeds.
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. Add slowly so the eggs don't scramble.
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. Once strained, stir in the Scotch/brown sugar mixture.
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. Sprinkle with some toffee bits for an extra special treat. You can purchase these on the baking aisle.