OLD-FASHIONED BUTTERSCOTCH PUDDING

Steps:

• Put egg yolks, cornstarch and salt into a large heatproof bowl, and whisk until the mixture is smooth and there are no lumps.
• In a medium pot over medium heat, combine brown sugar and butter, whisking, until the brown sugar melts, 1 to 2 minutes. Let cook, whisking constantly, until the mixture starts to smell like hot caramel and darkens slightly, about 1 minute longer. (Don't walk away, or the mixture may burn.)
• Immediately pour the milk and cream into the pot. (It will bubble fiercely and seize up.) Continue to cook, whisking constantly, until the clumps melt, 2 to 4 minutes.
• Slowly whisk about 1/2 cup of the hot cream mixture into the bowl with the egg yolks, whisking yolks until smooth, then whisk in the remaining hot cream mixture. Pour the egg-cream mixture back into the saucepan and place it over medium heat.
• Cook pudding, whisking constantly especially around the bottom and edges of the pot, until it comes to a full boil. (Don't worry about the eggs curdling. You're going to strain the mixture later.) Reduce heat to medium-low and cook, stirring the mixture constantly, until it thickens enough to mound thickly on the spoon, 4 to 7 minutes. If at any point the pudding looks curdled, whisk to help smooth it out.
• Strain mixture through a fine sieve into a heatproof container or bowl, then stir in the Scotch or bourbon, if using, and vanilla. To prevent a skin from forming, press plastic wrap directly onto the surface of the pudding. (If you like the skin, don't cover pudding until it cools.) Chill for at least 2 hours and up to 2 days.
• When serving, spoon pudding into dishes. Top with dollops of whipped cream, sour cream or crème fraîche, and any of the optional garnishes.