Cream the butter and brown sugar in a mixing bowl. Add the flour, eggs, vanilla, soda, quick oats and mix until blended. Spread 2/3 of mixture in the bottom of a 9 x 13 pan. Set aside.
In a double boiler melt the chocolate chips, condensed milk, 2T. butter and 2 t. vanilla until smooth. Pour chocolate mix over the base layer in the pan. Dot the top with the remaining 1/3 of the oatmeal mixture.
Bake at 350 degrees for 25-30 minutes or until golden.