Preheat oven to 325 degrees - have ready 2 baking sheets lined with parchment paper.
Cream thoroughly:
1 cup soft butter
1 cup powdered sugar
1 teasp. vanilla
Mix dry ingredients (below) together and then add them to the butter mixture:
1-1/4 cup flour
1/3 cup cornstarch
1 heaping tsp. espresso powder OR instant coffee
1/3 cup unsweetened cocoa powder
Make sure everything is mixed thoroughly. Divide dough into 4 equal portions. Roll each portion into a ball. Between 2 sheets of waxed paper, pat the ball into a 5-6" circle (about 1/4-1/3" thick) - carefully transfer the rounds onto opposite sides of the baking sheets. Score the rounds into 8 wedges, using a sharp knife.
Bake at 325 degrees for 23-25 minutes, or until the shortbread feels firm to the touch. Score each round again, cutting them through. Let cool completely on the parchment paper (slide onto wire cooling racks). Cut or break apart the wedges once they're completely cooled.
Melt white chocolate (Ghirardelli or other white chocolate coating) - use as little or as much as you'd like, depending on how chocolate-y you want these wedges. You can also leave them plain. Either dip the ends of the wedges into the chocolate or with a spoon or pastry bag, drizzle chocolate over the wedges.
