Grease a 8x2x2 inch baking pan, preheat oven to 350 ℉. In medium bowl partially melt chocolate, add butter and finish melting, stir in sugar. Add eggs and vanilla, beat lightly until just blended (do not over mix). Stir in flour, chocolate chips and nuts. Spread batter in pan, bake for 30 minutes. Cool, cut into bars.