1. Preheat oven to 350 degree F. Prepare Basic Dough; set aside.
2. For filling, in a medium saucepan combine chocolate pieces and condensed milk. Cook over low heat until chocolate melts, stirring occasionally. Remove from heat. Stir in walnuts and vanilla.
3. Press about two-thirds of the dough into the bottom of an ungreased 13x9x2-inch baking pan. Spread with filling. Dot remaining dough over the filling. Bake in preheated oven for 30 to 35 minutes or until golden. Cool in pan on a wire rack. Cut into bars. Makes 36 bars.