Melt butter in a medium saucepan. Add milk, brown sugar, and white sugar. Bring that to a boil and add graham cracker crumbs. Reduce heat to low and cook for 5-6 minutes.
Put a layer of Club crackers on the bottom of a 9 x 13 pan. Pour half of the graham cracker mixture over that. Add another layer of crackers, then the other half of the graham cracker mix, followed by a third layer of crackers.
Melt chocolate chips, butterscotch chips, and peanut butter. Use to frost the bars by spreading it evenly over the top layer. Chill. Cut. Enjoy!