Preheat oven to 325 degrees F (165 degrees C). Lightly
butter, or spray with a non stick vegetable spray, a 15 x 10 inch (38 x 25 cm) baking pan.
In a small bowl,
the confectioners sugar with the cocoa powder.
In another bowl,
sift the flour,
cornstarch and salt together.
In the bowl of your electric mixer (or with a hand
mixer), beat the butter until smooth. Add the
sugar and cocoa mixture and beat until fully incorporated.
Add the vanilla and espresso powder and beat until
add the flour mixture to the butter mixture and beat
until the dough just comes together.
dough over the bottom of the prepared pan and gently
press the dough, with your fingertips or the back of a spoon, to form an even
layer. Then, with a sharp knife, score the top of the shortbread into
approximately 3 inch x 1 inch (7 x 2.5 cm) fingers. Bake for 12 to 15 minutes, or until the top is dry and
a toothpick inserted in the center comes out clean. Remove from the oven and
place on a wire rack to cool. While the shortbread is still warm, re-cut the shortbread into
fingers. Cool completely before removing from pan.
If you want to garnish the shortbread fingers with white
chocolate; in a small heatproof bowl over a saucepan of simmering water, melt the white chocolate
with the vegetable shortening. Then place the melted chocolate into a paper cone or
pastry bag fitted with a 1/16 inch tip. Carefully pipe a thin line of chocolate
across the center of each cookie and then pipe another line across the first one
to make them look like presents. Don't worry about making your lines exact.
These shortbreads can be frozen.
Makes about 50