1 cup sweetened flaked coconut
5 oz. graham crackers
8 tbsp. unsalted butter
1 cup finely chopped walnuts (if you must)
1 cup semisweet chocolate chips
½ cup white chocolate chips
½ cup butterscotch chips
1 (14-oz.) can sweetened condensed milk
Adjust an oven rack to the lower-middle position and preheat the oven to 350° F. Line a 9×13-inch baking dish with aluminum foil and spray lightly with nonstick cooking spray. In a medium nonstick skillet over medium heat, toast the coconut, stirring occasionally until lightly browned and golden. Remove from the heat.
Place the graham crackers in a large zippered plastic bag. Using a rolling pin, crush the graham crackers to achieve a mixture of crumbs, bits and chunks. Meanwhile, place the stick of butter in the prepared baking pan and put it in the oven to melt, about 6 minutes. When the butter has melted, remove the pan from the oven. Add the graham cracker crumbs and toss lightly with a fork directly in the pan until all the butter is absorbed and the crumbs are evenly distributed over the bottom of the pan. In order, sprinkle the (nuts), chocolate chips, white chocolate chips, butterscotch chips, and toasted coconut over the graham cracker crumbs. Pour the condensed milk evenly over the entire dish.
Return the pan to the oven and bake until the top is golden brown, about 25 minutes. Cool on a wire rack to room temperature, about 2 hours. Remove the bars from the pan using the foil and transfer to a cutting board. Using a sharp knife, cut into bars of your desired size.