Make the dressing: combine the soaked dates (reserving the water), olive oil, lemon juice, dijon mustard, chopped ginger, ground coriander, chili flakes, cinnamon, salt, and pepper in an upright blender. Blend on high, stopping to scrape down the sides if necessary. Add a couple spoonfuls of the date soaking water to get the blade moving, if necessary. You want it totally pureed and almost creamy. I ended up using about 2 tablespoons of the water. Check the vinaigrette for seasoning, adjust, and set aside.