If the pistachio nuts have skins on them blanch them in hot (not boiling) water for 1 minute. Next place them into a spice grinder or food processor and grind until they are crumbs. Add 1-2 tbsp of water to create a paste. Set aside.
Make the ice Cream
Place a metal mixing bowl in the freezer for 5 minutes. Open the cocnut milk cans. Save the solid part of the milk (cream) and discard the liquid. Place cream in the standing mixer and whip until it's fluffy. Combine pistachio paste, vanilla extract and almond milk in the mixer. Add maple syrup 1 tbsp at a time until desired sweetness is reached. Blend until combined.
Transfer the ice cream mixture into a freezer safe container and freeze for 6 hours. Make sure the lid is tight or wrapped in foil and plastic wrap.