In a large mixing dish, combine the ground cookies or biscuits, coconut oil, salt, and nondairy milk.
Bake for 15 minutes after pressing this mixture evenly into the bottom of a 10-inch springform pan.
To make the base for this mousse, blend together the milk, cashews, coconut oil, lemon juice, sugar, salt, and vanilla in a blender.
In a small saucepan, combine the milk and agar powder. Allow for a 2-minute simmer while whisking.
Blend in the cashew mixture and matcha powder until well combined, adding more matcha if desired.
In a mixing bowl, combine all of the ingredients for this recipe; set aside to cool, then refrigerate for 5-6 hours or overnight.
Serve with a dollop of mousse on top and a dusting of extra matcha powder on top.