Step 1

For the butterscotch sauce: Melt the unsalted butter (4 tablespoons/57g) in a heavy bottomed sauce pan over medium heat. Once melted add the dark brown sugar (½ cup/100g), kosher salt (¼ teaspoon) and heavy cream (½ cup/120mL) and mix until fully combined.

Step 2

Bring the mixture to a low boil, stirring and scraping the sides of the pan occasionally and allow to boil for 4-5 minutes.

Step 3

Remove the pan from the heat and stir in the vanilla. Pour half of the butterscotch sauce into a heat proof container and half of the butterscotch into a bowl (I prefer a metal bowl) which is large enough to whisk the ice cream base into. Set aside while you make the ice cream. (The butterscotch sauce in the container can be stored in the refrigerator once it has cooled)

Step 4

For the ice cream base: In a small bowl, whisk the eggs (2 large).  Set aside.

Step 5

In a medium saucepan over medium-low heat, stir together the dark brown sugar (½ cup/100g), granulated sugar (½ cup/100g), half and half (1 cup/240mL) and ½ cup/120mL of milk*.

Step 6

When the mixture begins to simmer, remove it from the heat and quickly whisk half of the mixture into the beaten eggs.  Whisking quickly helps to keep the eggs from scrambling.

Step 7

Pour the egg mixture back into the saucepan and stir in the heavy cream (½ cup/120mL) and remaining ½ cup/120mL of milk.  Cook over medium-low heat, whisking constantly, until the mixture is thick enough to coat the back of a metal spoon, approximately 10 minutes. You don't want the mixture to boil.

Step 8

Remove the saucepan from the heat and whisk in vanilla (1 teaspoon).  Pour the ice cream base into the bowl with half the butterscotch sauce in it and whisk to fully combine. Cover the bowl with plastic wrap (press the wrap down onto the top of the ice cream base) and refrigerate until completely cool. (4 hours minimum and ideally 12-24 hours). I shoot for the ice cream to be cooler than 45°F.

Step 9

Pour cooled mixture into an ice cream maker and churn approximately 30 minutes (or according to the manufacturer's instructions). Pull the butterscotch sauce out of the refrigerator to warm up while you churn the ice cream**.

Step 10

Once ice cream has finished churning, move half the ice cream to a freezer safe container and top with half of the reserved butterscotch sauce. Then add the remaining ice cream and drizzle with the remaining butterscotch. Cover the container with it's lid or plastic wrap and store in the freezer.  (an air tight container is best)