Preheat your oven to 350°F (175°C). This ensures that your cookies bake evenly and come out perfectly golden.
Line a baking sheet with parchment paper. This will make it easier to remove the cookies once they’re baked.
In a large mixing bowl, beat the softened unsalted butter, light brown sugar, and granulated sugar until the mixture is smooth and creamy. This should take about 2-3 minutes.
Add the large egg and the vanilla extract to the butter mixture. Beat until well combined, ensuring everything is mixed thoroughly.
In a separate bowl, whisk together the all-purpose flour, cornstarch, baking soda, and salt (if using). Slowly add this dry mixture to the wet ingredients, mixing until just combined.
Gently fold in the coarsely chopped graham crackers, semi-sweet chocolate chips, butterscotch chips, and sweetened shredded coconut. Make sure the mixture is evenly distributed.
Using a cookie scoop or a tablespoon, drop rounded balls of dough onto the prepared baking sheet, leaving enough space between each cookie to allow for spreading.
Bake the cookies in the preheated oven for 12-15 minutes, or until the edges are lightly golden. The centers may look slightly underbaked, but they will continue to cook as they cool.
Once baked, remove the cookies from the oven and let them cool on the baking sheet for about 5 minutes. Then transfer them to a wire rack to cool completely. Now, they’re ready to be devoured!