Preheat oven to 350F and line two baking sheets with parchment paper or Silpat mats.

In a large mixing bowl, add the cornflakes, coconut and walnuts and mix to combine; set asideIn a small saucepan over medium heat, add the butter and both sugars and stir until the butter has melted and the mixture becomes a caramel.

Add the butter mixture to the cornflake mixture and stir well until completely combined (you can use your hands but be careful because the butter mixture will be hot).

Add the beaten egg and stir well until fully combined.With a tablespoon or large spoon, drop twelve mounds of the cookie mixture onto each of the prepared baking trays and, using your fingers, form them into mounds.Bake for 10 minutes or until golden brown.

Remove from oven and leave them on the trays to cool slightly (they will become firm as they cool). Transfer them to a wire rack to cool completely.  Store in an airtight container.