If not using a high-speed blender, soak the raw cashews overnight. Quick option: Boil for 10 minutes or soak in hot water for 1 hour.
Finely dice the pickles and onion. Set aside.
Drain and rinse cashews (if you soaked them). Add all ingredients to a blender except the diced pickles and onions.
Blend on high for 60–90 seconds, or until the dressing is completely smooth and creamy. Stopping to scrape down the sides, if needed.
Pour dressing into a bowl or mason jar and stir in the diced pickles and onions. Taste and adjust if needed—you can add more salt, pickle juice, or a touch of maple syrup.
Refrigerate for at least 30 minutes. This helps the flavors blend and the dressing thicken naturally (but if you really can't wait,enjoy immedianlty).
Notes
If you're using a high-speed blender (like a Vitamix or Blendtec), you can skip the soaking step.
I use a Medjool date, but you can also use 1 tablespoon maple syrup.