Soak cashew nuts in hot water for 30 min- 1 hour.
Make crust by adding walnuts and dates to a food processor. Blend/pulse a few times until small bits remain, with a sticky texture.
Add shredded carrots, ground cinnamon, and ground nutmeg. Pulse until carrots are incorporated, but don't over-blend.
Spread the mixture evenly into the 8-inch (20 cm) springform pan and press to the bottom of the pan. Place in the freezer while making the filling.
Rinse the food processor. Add soaked cashews, coconut milk, lemon juice, and agave syrup and blend for a few minutes, until very creamy and smooth.
Pour the mixture on top of the crust and spread evenly.
Place the cake into the freezer to firm for 3-4 hours or until the filling is semi-firm to the touch.
Before serving, thaw the cake on the counter for 15-30 minutes. Garnish with shredded carrots and walnuts (optional) and serve.