Blend the avocado, rice vinegar, maple syrup, salt, and pepper in a high speed blender.If you don't have a blender, mash the avocado very well with a fork. Then use a strong hand to whisk in the remaining ingredients.
Add the cabbage and carrots to a large bowl and pour on the avocado dressing. Toss well. Serve immediately or refrigerate 30 minutes to allow the flavors to blend. Garnish with fresh parsley.