Preheat the oven to 375 degrees. Line a baking sheet with parchment paper or a silpat mat.
Beat the butter and brown sugar together until smooth and creamy.
Add the egg and vanilla then beat until well combined.
Pour the oats, flour, cinnamon, baking soda, and salt together in a bowl; mix well.
Gradually add the oat mixture to the butter mixture until combined.
Add the crushed heath bars and half of the coconut. Mix until well combined.
Drop small rounded balls of cooking dough on the prepared baking sheet, about 2 inches apart.
Flatten the cookies a little bit then sprinkle some of the remaining coconut evenly on top of each cookie.
Place into the oven and bake for 9-10 minutes, or until slightly brown around the edges.
Remove from the oven and allow them to cool on the baking sheet for 3 minutes.
Transfer to a wire cooling rack to cool completely. Enjoy!