Mix butter, eggs, flour, baking soda, brown sugar, vanilla, salt and oatmeal together. Set asida. In separate bowl melt 1 package of chocolate chips, sweetened condensed milk and butter together. Add 1/2 tsp salt and 2 tsp vanilla to chocolate mixture. Press 2/3 oatmeal mixture into a greased 9 x 13 pan.Pour chocolate mixture on top. Cover with remaining oatmeal mixture. Bake at 350 degrees for 20 minutes