Step 1

Stir milk, cream, and brown sugar in a medium saucepan over medium-high heat until mixture comes to a rolling boil (it may look curdled which is fine).

Step 2

Meanwhile, whisk yolks, sugar, and salt in a medium bowl until mixture is pale yellow and sugar dissolves, a couple of minutes.Whisking yolk mixture constantly, slowly and gradually add 1/4 cup of hot cream mixture at a time (to prevent the eggs in the yolk mixture from scrambling.). Return to pan. Stir custard over low heat until thick enough to coat the back of a spoon, about 2-5 minutes (this isn't a terribly thick custard, it will be runny like a gravy).

Step 3

Place a medium metal bowl in a large bowl of ice water; set a fine-mesh sieve over metal bowl. Immediately strain custard into metal bowl. Let custard cool completely, stirring often.

Step 4

Stir 1 Tbsp. bourbon and vanilla into custard. Add more bourbon to taste by teaspoonfuls, if desired. Do Ahead: Custard can be made 1 day ahead. Cover and chill.

Step 5

Process custard in an ice cream maker according to manufacturer’s instructions. Transfer ice cream to an airtight container, cover, and freeze. Ice cream can be made 3 days ahead.

Step 6

Preheat oven to 375° F and line 2-4 baking trays with parchment paper.

Step 7

In a medium bowl, whisk together flour, soda, cinnamon, cloves, ginger and salt. Set aside.

Step 8

In the bowl of an electric stand mixer, beat together butter and granulated sugar on medium speed for 1 minute until light and fluffy. Add in the eggs and molasses, and beat on medium-low speed until combined. Gradually add in the dry ingredient mixture and beat until combined. Cover and refrigerate dough for at least 30 minutes, until it is chilled.

Step 9

Roll the dough into small balls, about 1-inch in diameter. Fill a small bowl with demerara sugar, and roll each ball in the sugar until it is completely coated. Place on cookie sheet at least 1 inch apart, then bake for about 8-10 minutes, until the cookies begin to slightly crack on top. (They may crack more while cooling.) Remove from the oven and let cool for a minute or two. Then transfer to wire racks to cool completely.

Step 10

Use immediately or store in a sealed container for up to 1 week.

Step 11

To assemble:Using an ice cream scoop, scoop ice cream onto one cookie and place another cookie on top. Eat immediately, or place in freezer to firm up (at least 30 minutes).