Preheat the oven to 350 degrees. Line a 9 x 13 baking pan with parchment paper or tin foil (make sure it is longer than the pan so you can use the ends as handles to easily remove it from the pan). COAT PARCHMENT PAPER OR TIN FOIL WITH COOKING SPRAY.
Melt butter in a large bowl in the microwave then add the graham cracker crumbs to it. Mix well to combine then press crumb mixture evenly into the lined baking pan. Pour the sweetened condensed milk evenly over the crumb mixture.
Layer evenly with half of the coconut, chocolate chips, white chocolate chips, butterscotch chips, and toffee bits. Repeat using the remaining ingredients.
Place into the oven and bake for 30 minutes, or until the top is just starting to brown. Remove from the oven and let cool. Place into the refrigerator for 2 hours to let the bars completely set.
Remove from the refrigerator and make sure the center of the bars is set. Carefully remove the bars from the pan holding onto the excess ends of the parchment paper (or tin foil). Place on the counter.
Remove the bars from the parchment paper or tin foil then place them on a cutting board. Cut into small squares because they are very rich and decadent. Serve with cold milk. Enjoy.