Soak your cashews for at least 2-3 hours, if not overnight. You could also try a quick soaking method if you're in a rush - soak them in very hot water for 15-20 minutes (let the water boil then cool it for a couple of minutes prior to pouring it over the nuts).
Make the cranberry mixture by adding the cranberries, water, and maple syrup to a small pan on medium-high heat for 5-7 minutes. Set aside to cool once the cranberries have softened.
Grease a 12-slot muffin tin (I used cooking spray). Make the crust by adding the dates to a food processor. Process until they form a ball. Take the ball out of the food processor. Add the walnuts to the food processor and process until fine. Add the dates back in and process until mixed. Divide the crust evenly between the 12 slots in the muffin tin. Press the crusts down firmly (I like to use the bottom of a glass to do this). Put the muffin tin in the freezer.
I like to rinse the bowl of the food processor off at this point (up to you). Add the soaked cashews, coconut milk (if it's separated then aim to get a lot of the coconut cream), cranberry mixture, maple syrup, lemon juice, and vanilla to the food processor. Blend until smooth (this may take a few minutes), stopping to scrape down the sides occasionally.
Take the muffin tin out of the freezer and add the filling to each of the 12 slots as evenly as possible. Cover with plastic wrap and freeze for at least 4 hours.