Line a 5"x10" loaf pan with parchment paper.
Begin by preparing the cookie dough. Once it's prepared, scoop out scant ½ teaspoon mounds and roll into mini cookie dough balls (no more than ¼- to ⅓-inch diameter). Alternatively, for a fuss-free version, simply press and compact the cookie dough into an even, ⅓-inch-thick layer, and slice into ⅓-inch cubes. Chill the dough balls (or cubes) in the freezer until ready to use.
In a high-speed blender, combine the cashew milk, dates, cashew butter, vanilla, and sea salt. Blend on high for 3 to 4 minutes or until completely smooth.
Pour about half of the ice cream base into the lined pan and top with about half of the cookie dough balls. Use the pointy end of a chopstick or a toothpick to gently mix into the ice cream base. Top with the remaining ice cream base and the remaining cookie dough balls. Again, use a toothpick or chopstick to very lightly mix into the ice cream base, allowing some of the cookie dough balls to remain floating at the surface.
Loosely cover with plastic wrap and freeze for at least 8 hours, or until the ice cream has set.
Let the ice cream stand at room temperature for at least 20 minutes before scooping or serving. Dip an ice cream scoop in hot water and use it to scoop the ice cream.
Store in the freezer, loosely covered, for up to one week.