Beat butter in the bowl of a stand mixer (or using an electric beater) for about 30 seconds. Add sugars and beat until light and fluffy (pause to scrape down sides and bottom of bowl, if needed).
Add eggs, one at a time, beating until combined.
Stir in vanilla and coconut extract.
In a separate bowl, whisk together flour, cornstarch, baking soda, and salt.
Gradually add flour mixture to butter mixture until completely combined. Be sure to scrape the sides and bottom of the bowl so ingredients are well-mixed.
Gradually stir in 3 cups coconut flakes and caramel chips until completely combined.
Chill dough in refrigerator for 30 minutes.
Preheat oven to 375F (190C) and prepare cookie sheets by lining with parchment paper.
Drop cookie by rounded 2-3 Tablespoon-sized ball onto parchment paper, spacing at least 2" apart (for very round cookies, briefly roll between your hands to form into smooth balls).
Bake on 375F (190C) for 10-12 (edges should be slightly browned, centers may still be slightly underbaked but shouldn't be raw, they'll bake completely as they cool).
Allow cookies to cool completely on cookie sheet before dipping in dark chocolate (if using).
If dipping in chocolate: Prepare melting wafers according to package instructions, heating until melted.
Dip cookies about ½-way into the chocolate and transfer to wax paper. Sprinkle with remaining ½ cup coconut (if using) and allow chocolate to set before serving.
*½ cup of this coconut is for toasting, which is optional. You can add untoasted coconut or no coconut on top at all (there's plenty inside the cookies!)If you do want to make and add toasted coconut, spread the ½ cup of your remaining coconut evenly across a parchment paper lined cookie sheet and bake in a 325F (190C) oven for about 5-7 minutes or until lightly golden brown. Allow to cool before sprinkling over dark chocolate, but sprinkle immediately after dipping in chocolate or it won't stick!**Alternatively you can use 1 ½ cups of melted semisweet chocolate chips or chocolate bar, just keep in mind that the chocolate will take much longer to harden.