In medium bowl, stir together brownie mix, water, oil, 1 egg and espresso powder until moistened (about 40 strokes). Spoon batter into lightly greased 13x9-inch pan. Bake for 12 minutes.
Place cream cheese and sugar in medium bowl. Using an electric mixer, mix on low speed 1 minute or until smooth. Add melted chocolate and mix on low speed until blended. Add 3 eggs, espresso powder and vanilla and continue to mix on low speed until blended. Spoon cream cheese mixture over crust and spread evenly. Bake 25-30 minutes or until filling is set temp around 325 to 350 is fine. Cool thoroughly before cutting. Garnish with whipped cream and chocolate shavings, if desired. Store in the refrigerator.