Gradually add sugar to eggs. Melt chocolate with butter; stir into eggs.
Sift together flour, baking powder and salt. Add to first mixture with nuts and vanilla.
Bake in greased 15½ X 10½ X 1" jelly roll pan in moderate oven (350°) 12 to 15 minutes. Cool slightly in pan; dust with confectioners sugar. Cool completely in pan on rack; cut in diamonds, tri