Place the cashews in a heat resistant bowl. Bring 4 cups of water to a boil and pour it over the cashews.
When the cashews have soaked for two hours, it's time to prepare your ice cream base. Pour them into a strainer and then add the strained cashews to your blender container.
Add all the remaining ingredients (maple syrup, coconut cream, coconut milk, vanilla extract, 1.5 teaspoons dark rum, nutmeg, salt and egg yolks if using) to the blender container. If you're using a high-speed blender, blend the mixture on high for about 2 minutes. If you're using a regular blender, blend for 3-4 minutes to make sure it's smooth. Taste and add 1.5 teaspoons - 1 tablespoon additional rum if desired.
The ice cream mixture will become warm during the blending process, so when you're finished put it in the fridge to chill for about 30-45 minutes. I leave mine in the blender container.
When the ice cream base has chilled, pour it into your ice cream maker and churn according to your manufacturer's instructions.
When the ice cream is ready it should have a soft serve consistency. You can eat it right away, or if you prefer a firmer consistency transfer it into an airtight container and place in the freezer for 2-4 hours. I like to use a glass loaf pan with a lid. If the ice cream becomes too firm, let it soften at room temperature for 5-15 minutes before scooping.