Preheat oven to 350°.
Whisk together flour, sugar, and coffee granules.
With an electric mixer add butter and vanilla, beating until well blended.
Stir in 1 cup of chocolate chips.
Spread into an ungreased 8" square pan.
Bake at 350° for 20 minutes or until lightly browned.
Let set for 5 minutes then cut into squares while still in the pan.
Melt ¼ cup bittersweet chocolate and drizzle over the top of the shortbread.