Preheat oven to 350F for cookie base and topping. Beat together butter and sugar until light and fluffy. Blend in egg and vanilla. Add combined flour, soda and salt; mix well. Stir in oats. Press half of mixture onto bottom of greased 13 x 9 inch baking pan. Reserve remaining mixture for topping.
Melt together chocolate, condensed milk butter and salt, in a heavy saucepan over low heat until smooth. Stir in nuts and vanilla. Spread evenly over base mixture. Sprinkle reserved cookie base and topping mixture evenly over chocolate layer; press down slightly Bake in 350F degree oven for about 35 to 40 minutes.
Cool; cut into 1-inch to 1-1/2-inch squares.
Cajun Country -- New Iberia, Louisiana