1 c. butter, softened
1 c. brown sugar
1 lg. egg yolk
1 1/2 t. Vanilla
3 T. instant espresso powder dissolved in 2 T. boiling water
2 c. flour
1/2 t. salt
8 oz. fine quality bittersweet chocolate, finely chopped
3/4 c. salted roasted cashews (4 oz.), chopped

1. Heat oven to 350° F.
2. Beat together butter and brown sugar until pale and fluffy
3. Add yolk and vanilla. Add espresso mixture
4. Add flour and salt and combine at low speed until just mixed
5. Spread batter in an ungreased 10.5"x15.5" baking pan
6. Bake in the middle of the oven until the top puffs slightly, the sides pull away from the edges, about 16-22 minutes
7. While the base is baking, melt chocolate in a double boiler
8. Spread the chocolate over the warm base and immediately sprinkle with cashews
9. Cool completely in pan, on rack
10. Cut into 48 bars
11. Chill until firm, about 15 minutes