These sweet little treats are so easy to make and take just 15 minutes to put together. The graham cracker crumbs and sweetened condensed milk magically come together to make an ooey-gooey bottom layer.
Preheat the oven to 350ºF. Butter a 9-by-13-inch baking dish.
Combine the melted butter and graham cracker crumbs in a small bowl with your hands (the mixture should hold together when squeezed). Pour the mixture into the prepared dish and press it into the bottom in an even layer, using the bottom of a measuring cup to help. Pour the sweetened condensed milk over the crumbs, then sprinkle the chocolate chips, butterscotch chips, pecans and coconut over the milk.
Bake until the sides are golden brown and begin to pull away from the dish, 30 to 40 minutes. Let cool completely in the dish. Cut into 48 small pieces (they are rich). The cookies can be refrigerated in an airtight container for up to 3 days.