Step 1: Prepare the Custard Base

1. In a medium saucepan, combine heavy cream, milk, sugar, molasses, and spices.
2. Heat over medium-low, whisking occasionally, until it almost simmers (don’t let it boil).

Step 2: Temper the Egg Yolks

1. In a separate bowl, whisk the egg yolks until smooth.
2. Slowly pour a ladle of the warm cream mixture into the yolks while whisking constantly (to prevent curdling).
3. Gradually pour the tempered yolks back into the saucepan, stirring continuously.

Step 3: Cook Until Thickened

1. Cook over low heat, stirring constantly, until the custard thickens and coats the back of a spoon (about 170°F).
2. Remove from heat and stir in orange zest, if using.

Step 4: Chill the Custard

1. Strain the custard through a fine-mesh sieve into a bowl.
2. Set over an ice bath to cool quickly.
3. Cover and refrigerate for at least 4 hours (or overnight for best results).

Step 5: Churn the Ice Cream

1. Pour the chilled custard into an ice cream maker.
2. Churn according to manufacturer’s instructions until thick and creamy.
3. During the last few minutes, fold in crushed ginger snap cookies (optional).

Step 6: Freeze & Serve

1. Transfer to an airtight container, pressing parchment paper on top to prevent ice crystals.
2. Freeze for at least 2 hours before serving.