Freeze the bowl of the ice cream maker. At least 24 hours before you want to make homemade ice cream, freeze the bowl of the ice cream maker. The bowl needs to be fully chilled for the ice cream to firm up.
Blend. Add the full-fat coconut milk, cashews, maple syrup, coconut oil, and vanilla to a high-speed blender and blend on high until smooth.
Chill (optional). If the ice cream mixture gets too warm during blending, pour the mixture into an airtight container and transfer it to the refrigerator to chill. The mixture should be cold before churning.
Churn. Pour the ice cream mixture into the ice cream maker and let it churn according to the manufacturer's instructions. I have the Cuisinart Ice Cream Maker and typically churn the ice cream base for about 20 minutes.
Freeze. The ice cream will have a soft texture immediately after churning, similar to soft-serve ice cream. To achieve a more scoopable consistency, transfer the churned ice cream to a freezer-safe container and freeze it until scoopable, for 2-4 hours, depending on how firm you like your ice cream and how deep/shallow your ice cream container is. I used an 8.5 x 4.5 x 2.0-inch stainless loaf pan.
Churning Without an Ice Cream Maker. Pour the ice cream mixture into a shallow pan and keep checking on it every 30 minutes after it's been placed in the freezer. As the ice cream begins to freeze near the edges, remove it from the freezer and stir it vigorously with a spatula, whisk, or hand mixer (a hand mixer will give you the best results). Really beat it up and break up any frozen sections. Then, return the ice cream to the freezer. Keep checking periodically and stirring (by hand or with the electric mixer) while the ice cream freezes until completely frozen. It will likely take a few hours to be ready. Note: manual churning will never create the same texture as an electric ice cream maker.
Store. Leftover vanilla ice cream keeps well in an airtight container in the freezer for up to 1 month.