1. Melt margarine over medium heat. Remove from heat and stir in sugar, vanilla, and flour.
2. Pat dough into an 11- x 16-inch pan and bake for 20 minutes until firm but still tender. Remove from oven and immediately sprinke with chocolate chips. Let the chocolate chips melt and smooth them over the cookie base.
3. Sprinkle with chopped nut brittle or Viennese crunch (or a similar topping of your choice.) These are my favorite as they are both elegant and delicious.
4. Let the bars cool and as they cool the chocolate will set until they are hard enough to cut. Slice the bars into small squares or into triangles etc… Enjoy! They are addictive!