1. Preheat oven to 350 degrees F. Grease 13 by 9 inch baking dish.
2. Melt one cup chocolate chips and butter in large heavy duty saucepan over low heat, stir until smooth. Remove from heat.
3. Stir in eggs, flour, sugar, vanilla, and baking soda. Stir in remaining morsels and nuts. Spread into pan.
4. Bake for 18 to 22 minutes. Cool completely in pan on wire rack.