Preheat your oven to 350°F (175°C). Line a 9x13 inch baking pan with parchment paper, leaving an overhang on the long sides for easy removal later.
In a small bowl, mix the melted unsalted butter and the graham cracker crumbs until the mixture resembles wet sand.
Pour the crumb mixture into the prepared pan. Use your hands or the bottom of a measuring cup to press the crumbs firmly and evenly into the bottom of the pan to form the crust.
Pour the sweetened condensed milk evenly over the graham cracker crust. Use a spatula to spread it all the way to the edges.
Layer the remaining ingredients evenly over the wet milk in this exact order: semi-sweet chocolate chips, butterscotch chips, chopped nuts, and finally the sweetened shredded coconut.
Gently press down on the coconut layer with the palm of your hand or the back of a fork so that all the chips and nuts sink slightly into the condensed milk to bind.
Bake for 25-30 minutes, or until the coconut is deeply golden brown and the edges are bubbling.
Remove from the oven and let the pan cool completely to room temperature.
Once entirely cooled, use the parchment overhang to lift the block out of the pan. Place on a cutting board and slice into 24 squares.