Butterscotch Pudding

Set a fine-mesh sieve over a medium bowl and place it near the stove.   

In a large saucepan, whisk the cornstarch, salt, yolks, and 1/2 cup (107g) brown sugar vigorously for about 1 minute, until smooth, slightly thickened, and lightened in color. At first the mixture will appear too thick to whisk, but it will gradually smooth out. 

While whisking, slowly pour in the milk and cream; continue to whisk until smooth. Add the remaining 1 cup (213g) brown sugar and whisk to combine. 

Place the saucepan over medium heat and cook, stirring constantly with a heatproof rubber spatula and scraping the bottom and corners of the pan, until the mixture has thickened enough to begin to coat the spatula where it contacts the bottom of the pan, about 10 to 15 minutes.

Switch to a whisk and continue to cook, whisking constantly as the mixture continues to thicken. Once you see the first bubble burst on the surface, continue to whisk for 1 more minute. The mixture will not come to a rolling boil, but there will be slow bubbles that pop across the surface. 

Remove the saucepan from the heat and whisk in the butter, vanilla, and Scotch until incorporated and the pudding is smooth and shiny. Immediately press the pudding through the sieve to remove any lumps. Transfer the butterscotch pudding to a serving bowl or portion it into individual ramekins or small cups or jars. 

Press plastic wrap or parchment directly onto the surface of the pudding to prevent a skin from forming. Chill until set, about 3 hours. Serve with a spoonful of whipped cream.

Butterscotch pudding will keep, covered, in the refrigerator for up to 5 days.