Butterscotch Pudding (Cook's Illustrated)

Ingredients

• 12 tablespoons unsalted butter, cut into 1/2 inch pieces
• 1/2 cup sugar
• 1/2 cup packed dark brown sugar
• 1/4 cup water
• 1 tablespoon light corn syrup
• 1 teaspoon lemon juice
• 3/4 teaspoon salt
• 1 cup heavy cream
• 2 cups whole milk, plus 1/4 cup
• 4 large egg yolks
• 1/4 cup cornstarch
• 2 teaspoons vanilla extract
• 1 teaspoon dark rum, optional

Directions

1. Bring butter, sugar, brown sugar, water, corn syrup, lemon juice, and salt to a boil in a large saucepan over medium heat, stirring occasionally to dissolve the sugar and melt the butter.
2. Once the mixture is at a full rolling boil, cook, stirring occasionally, for 5 minutes. (Caramel will register 240 degrees.)
3. Immediately reduce heat to medium-low and gently simmer (the caramel should maintain a steady stream of lazy bubbles; if not, adjust heat accordingly), stirring frequently, until the mixture is the color of dark peanut butter, 12-16 minutes longer (caramel will register about 300 degrees and should have a slightly burnt smell).
4. Remove pan from heat; carefully pour 1/4 cup cream into the caramel mixture and swirl to incorporate (mixture will bubble and steam); let the bubbling subside.
5. Whisk vigorously and scrape the corners of the pan until the mixture is completely smooth, at least 30 seconds.
6. Return pan to medium heat and gradually whisk in the remaining 3/4 cup cream until smooth. Whisk in 2 cups milk until the mixture is smooth, making sure to scrape the corners and edges of the pan to remove any remaining bits of caramel.
7. In the microwave, heat the remaining 1/4 cup milk until simmering, 30-45 seconds.
8. Whisk egg yolks and cornstarch together in a large bowl until smooth. Gradually whisk in the hot milk until smooth; set aside.
9. Return the saucepan to medium-high heat and bring the mixture to a full rolling boil, whisking frequently.
10. Once the mixture is boiling rapidly and beginning to climb toward the top of the pan, immediately pour into the bowl with the yolk mixture in one motion (do not add gradually). Whisk thoroughly for 10-15 seconds (mixture will thicken after a few seconds). Whisk in the vanilla and rum.
11. Spray a piece of parchment paper with vegetable oil spray and press onto the surface of the pudding. Refrigerate until cold and set, at least 3 hours.
12. Whisk pudding until smooth before serving.