In double boiler, mix chocolate, milk, butter and salt. Stir until smooth. Add nuts and vanilla.
Cream together butter and sugar. Add eggs and vanilla. Sift dry ingredients. Stir in oats and dry ingredients.
Spread 2/3 of oatmeal mixture in bottom of greased 15 x 10 x 1 inch pan. Cover with chocolate filling. Dot with remainder of oatmeal mixture and swirl over chocolate filling. Bake 25-30 minutes at 350 degrees.