Preheat oven to 190ºC Mix butter, sugars and vanilla thoroughly. Beat in egg. Blend in flour, soda and salt and mix. Spread in greased 13x9x2 inch pan, sprinkle with chocolate chips and nuts over the top, and place in oven for one minute. Remove and run knife through dough to marbelize, return to oven and bake at 190ºC 12-14 minutes. Makes 2 dozen. ----