1

Melt butter and chocolate in a medium saucepan over moderate heat. Remove from heat. Beat in sugar gradually with a wooden spoon until thoroughtly combined. Add eggs, one at a time, beating well after each addition. Stir in vanilla. Stir in flour until thoroughly combined. Stir in 1 C of the walnuts. Spread into a greased 13x9x2" pan.

2

Combine remaining 1/2 C walnuts with chocolate pieces. Sprinkle over top of cookie mixture, pressing down lightly.

3

Bake in a moderate oven 350° for 35 minutes, or until top springs back when lightly pressed with fingertip. Cool completely in pan on wire rack. Cut into bars.