Preheat oven to 350 degrees Fahrenheit, or 325 if using a glass pan.
Add the stick of butter to a 9x13 inch pan and place in the oven just until the butter in melted.
Crumble the graham crackers and sprinkled them over the melted butter and mix together.
Press the graham cracker crumb mixture evenly to create a crust.
Sprinkle half the chocolate chips over the crust.
Evenly spread the coconut over the chocolate chips.
Sprinkle the remaining chocolate chips over the coconut.
Add the chopped nuts if using.
Drizzle the sweetened condensed milk over the top.
Bake for 25 minutes until lightly golden brown.
Allow to cool completely before cutting.
Cover and store up to 3 days. We like ours best refrigerated.