Combine bananas, cocoa, coconut milk and vanilla in the jar of the blender. Blend until very smooth (like thin cake batter), stopping to scrape down the sides of jar and star mixture 2 or 3 times to ensure all banana is pureed.
Pour banana puree into baked pie crust. Sprinkle peanuts and chocolate across surface of pie. Cover very tightly with plastic wrap and freeze for a minimum of 4 hours, or overnight.
To serve, remove plastic wrap and set at room temperature for about 30 minutes (longer if pie was frozen for more than 4 hours), until pie is just soft enough to yield to the cut of a knife.