Thinly slice the cucumbers and dice the avocados. Finely chop the red onion.
In a small bowl, whisk together the extra-virgin olive oil, apple cider vinegar, and maple syrup. Season with salt to taste.
In a large bowl, gently toss the cucumbers, avocados, and red onion with the dressing.
Stir in the chopped cilantro and mint.
If using, sprinkle the toasted coconut flakes on top.
Chill the salad for about 15 minutes before serving to allow the flavors to meld.