In a food processor, process the nuts and the chopped dates together until broken down & combined
Add the lime zest if using , vanilla extract, and salt and process a few times until combined. Add the coconut oil last.
Line a 6″ square or round spring form cake tin with parchment paper and press the dough evenly on the base. Rub a little coconut oil around the inside of the tin. Place into the freezer for 30 min until it firms up.
To prepare the filling, rinse the cashews and drain them well.
Melt the coconut oil ideally in a water bath.
Blend all ingredients together (except coconut oil) in a high-speed blender until you reach a nice and smooth consistency. You will have to stop to scrape the edges as you go.
Stream in melted coconut oil and blend until incorporated. Pour the filling over the base.
Use the back of a spoon or palette knife to flatten it and freeze till set (at least 3 hours) Remove from freezer approx.. 1h before serving, cut into slices.