In saucepan over boiling water, mix chocolate chips, sweetened condensed milk, butter and salt. Stir until mixture is smooth. Add nuts and vanilla. Spread about 2/3 of oatmeal mixture in bottom of a greased 15 1/2 x 10 1/2 x 1 inch jelly roll pan. Cover with chocolate mixture and swirl it. Spread remaining 1/3 oatmeal mixture over the top. Bake at 350° for 25-30 min or until lightly browned.
Makes about 60 - 2 inch bars.