In small bowl, gradually stir 1/2 cup/125 mL of the milk into cornstarch; set aside.

In separate bowl, beat egg yolks with 1/4 cup/60 mL of the milk; set aside.

Stir cream with remaining milk; warm and set aside.

In heavy-bottomed pot over medium-high heat, boil sugar, salt and 1/2 cup/125 mL water, without stirring but occasionally swirling pan, until amber coloured; reduce heat to medium-low and, swirling pan, cook until nutty brown. Remove from heat; gradually stir in cream mixture, pausing whenever caramel mixture foams up.

Whisk cornstarch mixture until smooth; whisk into caramel mixture. Cook over medium heat, lightly whisking, until mixture begins to simmer. Stir in bourbon and return to simmer; reduce heat to low and continue cooking, whisking constantly, for 3 minutes.

Slowly whisk about 1 cup/ 250 mL of the caramel mixture into the egg mixture; stir egg mixture into pan and cook, stirring and keeping pudding just below simmer, for 2 minutes.

Through fine sieve, strain into bowl; stir in vanilla and butter, stirring for about 2 minutes until butter is completely melted and blended, and mixture is slightly cooled. Place plastic wrap directly on surface; let cool. Refrigerate for at least 2 hours or for up to 2 days.

Makes 6 to 8 servings.