Sift together the flour, baking soda and salt; set aside. In a medium bowl, cream together the melted margarine, brown sugar and white sugar until well blended. Beat in the vanilla, egg, and egg yolk (eggs should be room temperature) until light and creamy (don't over beat.) Mix in the sifted ingredients until just blended. Stir in the chocolate chips by hand using a wooden spoon. Refrigerate batter for 1 hour. Preheat the oven to 325°F (165°C) Drop cookie dough on cookie sheets. Cookies should be about 3 inches apart. Bake for 15 to 17 minutes or until the edges are lightly toasted. Cool on baking sheets for a few minutes before transferring to wire racks to cool completely.