Preheat oven to 180°C/350°F. Grease baking dish. Melt some of the chocolate chips and butter in large saucepan over low heat, stirring occasionally until smooth. Remove from heat.
Beat in eggs, then fold in flour, sugar, vanilla extract, and baking soda. Stir in remaining chocolate chips and nuts.
Spread batter evenly into greased baking dish.
Bake at 180°C/350°F for approx. 18 – 22 min., or until a toothpick inserted into the center comes out slightly sticky. Cool completely in pan on wire rack. Enjoy!