In a 13x9x2-inch baking pan, melt the butter or margarine. Sprinkle crushed graham crackers evenly over bottom of pan. Top with the peanut-butter-flavored pieces, the butterscotch-flavored pieces or white baking pieces. Top with the chocolate pieces. Sprinkle with the flaked coconut and chopped walnuts, macadamia nuts, or pecans. Drizzle sweetened condensed milk evenly over top.
Bake the cookies in a 325 degree F oven for 30 to 35 minutes or until the edges of the bar cookies are a golden brown.
Cool in pan on a wire rack 30 minutes. Cut into bars. When completely cool, transfer to a serving plate. Or store in covered plastic container at room temperature.