Cover 2 cups raw cashews with water and soak for 15-30 minutes.
Drain the cashews and put into a powerful blender or a food processor. Add 1 ½ cups cold water, ¾ cup unsweetened creamy peanut butter½ cup maple syrup and 1 teaspoon fine sea salt. Split the vanilla bean and scrape the seeds into the mixture. Puree until very smooth, thick and creamy (if the mixture becomes too thick to blend, add more water one tablespoon at a time until it's the right consistency).
Make the crust:
Process 2 cups raw walnuts or almonds in a food processor until they look like coarse flour. Add ¼ cup cocoa powder, 3 tablespoons maple syrup, 1 tablespoon melted coconut oil or vegetable oil, 1 teaspoon vanilla extract, and ¼ teaspoon sea salt and pulse until mixed. Press the crumbs into the bottom of a 9-inch deep pie dish or tart pan with 2-inch sides.
Pour the filling into the crust and place in the freezer for 10 minutes.
Put the chocolate in microwaveable dish and heat on high in 30 second increments, stirring each time, until it's melted. Spoon some of the chocolate in random blobs over the top of the filling (save the rest for serving). Use a skewer or thin knife and swirl the chocolate into spirals (be sure not to touch the crust layer).
Cover the pie and freeze until firm, about 2 hours, then transfer to the refrigerator. Serve drizzled with more melted chocolate and sprinkled with peanuts.
Notes
You need a 9-inch deep-dish pie plate, or a 9-inch tart pan with 2" inch sides (also known as a quiche pan).