Pour the coconut milk into an ice cube tray and freeze for at least 4 hours or ideally overnight. I find it easiest to use a jug to pour the coconut milk into the ice cube mould.
Prepare the cookie dough by mixing the oat flour (see notes below for instructions to make your own oat flour), cashew butter, and agave syrup in a medium bowl using a spatula until a dough forms. Stir in 1/4 cup/ 40 grams of the chocolate chips.
Taking 1/2 tsp of the cookie dough at a time, roll into balls and place on a plate or baking tray. If you are finding the dough too sticky, add more oat flour, and if it is too dry, add some more agave syrup. Transfer the cookie dough balls to the freezer to firm up whilst you prepare the ice cream base.
Remove the coconut milk ice cubes from their mould and place in a large blender jug (I use a vitamix - please make sure your blender can handle ice cubes!). Add the dairy-free milk, agave syrup, coconut oil, and vanilla extract to the blender. Blend on medium-low speed until the ice cream is smooth and creamy.
Stir most of the cookie dough balls and remaining chocolate chips into the ice cream base, reserving a few for topping. You can enjoy the cookie dough ice cream now for more of a soft-serve texture, but I prefer to transfer the mixture to a loaf tin, top with the remaining cookie dough and chocolate chips, and freeze for 1-2 hours for a more scoop-able texture. Enjoy!