When I make cashew cream, I use equal amounts of water and cashews and just grind them up all at once for a minute or so on speed 9. If I want it thicker, I use double the amount of cashews as water.
Or here's another way for a fancier sweet version:
Blend 1 cup cashews and 1 cup water for 1 min, sp 9. Insert butterfly, drizzle 1 - 1/2 cups sunflower oil through hole in lid while mixing on speed 4, until cream thickens. Blend in 4 tablespoons pure maple syrup, 1/2 tsp vanilla extract and pinch salt (briefly). Chill and serve. (Thickens substantially when chilled.) [from Fit for Life Cookbook]