Line a standard muffin tin with 6 parchment baking cups, and set aside.
To prepare the crust:
Pulse the walnuts or pecans in a mini food processor or blender, until a fine powder is formed. (Be careful not to over-process, as you don't want it to become a nut butter.) Add in the melted coconut oil, maple syrup, vanilla extract and salt, and pulse again until a uniform dough is created.
Scoop the dough by a heaping tablespoon, and drop it into the bottom of each of the 6 baking cup liners. Use your fingers to press the crusts down firmly, and place the pan in the freezer to set.
To prepare the filling:
Place the dry cashews in a blender and blend until a it's nearly the texture of a creamy cashew butter. Add in the rest of the filling ingredients, and blend until a silky smooth batter is formed. Adjust flavors to taste, keeping in mind that the final chilled desserts will taste slightly less-sweet than the room-temperature batter.
*Note: If you're using prepared cashew butter instead of the whole cashews, you can skip the blender all together and mix all of the filling ingredients well in a medium bowl.
Remove the pan of crusts from the freezer, and divide the filling batter evenly among the six cups. Return to the freezer to set for at least 3 hours before serving, or until they are completely firm.
Serve directly from the fridge or freezer for best texture, and keep any leftovers well chilled.