Melt 1 C. butter, mix together with brown sugar, eggs, flour, salt, vanilla, nuts, coconut.
Melt chocolate chips, 2 Tbl. butter and sweetened condensed milk over boiling water, stirring until smooth.
Spread 1/2 of brown sugar dough into a 9x13 baking pan. Spread chocolate mixture. Spread remaining brown sugar dough over chocolate and swirl slightly.
Bake at 350 degrees for 35-40 minutes.