Heat oven to 350°F. In large bowl, break up cookie dough. Stir in cashews and white chocolate chunks. Drop dough by heaping teaspoonfuls onto ungreased cookie sheets.
Bake 9 to 12 minutes or until golden brown. Immediately remove from cookie sheets; place on wire racks.
While cookies are baking, in 1-quart saucepan, cook butter over medium heat, stirring constantly, until light golden brown. Remove from heat. Stir in remaining icing ingredients until smooth.
On top of warm cookies, immediately spoon about 1 teaspoon icing (if icing becomes too thick, reheat over low heat).