Grandma Greenwood's 7 layer bars

1 stick butter
1 C crushed graham crakers
1 12 oz package butterscotch chips
1 C coconut
1 12 oz package chocolate chips
1 C chopped nuts (optional)
1 C sweetened condensed milk

Melt butter in 9 x 13 pan in oven
Add ingredients in order listed
Bake in oven at 350 for 20 minutes
Let cool before cutting