Step 1

Melt butter in a heavy bottomed saucepan.

Step 2

Add the brown sugar, and cook over medium-high heat until the sugar caramelizes and the butter browns, stirring constantly. First it will be hard to mix the butter and sugar, then it will smooth out. After a few minutes of stirring, it will break again, and the butter and sugar will be separate. Keep cooking and stirring until the mixture comes back together for a second time and darkens in color. You may see a few wisps of smoke.

Step 3

Once the butterscotch has finished cooking, carefully add 2 cups of the whole milk. The butterscotch will harden into a clump. Worry not. Cook and stir over medium-low heat until the butterscotch melts.

Step 4

Whisk the cornstarch and salt into the other 2 cups of milk and then whisk into the butterscotch.

Step 5

Bring to a boil, stirring frequently, and allow the mixture to boil for about 1 minute.

Step 6

Turn the heat off and whisk in the softened cream cheese until completely incorporated and smooth. Stir in the vanilla.

Step 7

Let the base cool for an hour on the counter, whisking occasionally, and then chill the ice cream base at least 6 hours or overnight.

Step 8

Freeze according to manufacturer's instructions and pack into a container to freeze throroughly.

Step 9

Pour the finished base into a large bowl.

Step 10

Cool the base for an hour on the counter, whisking occasionally, and then chill the ice cream base at least 6 hours or overnight.

Step 11

Whisk the base thoroughly to incorporate a bit of air and freeze for an hour.

Step 12

Remove the base from the freezer and whisk very well, being sure to scrape the frozen parts around the edges into the whole.

Step 13

Return to the freezer and repeat steps 3 and 4 at least 2 more times and possibly 3, until the base is the consistency of soft serve ice cream.

Step 14

Pack into an airtight container to freeze thoroughly, at least 4 hours or overnight.