1Heat oven to 375°F. In 2-quart saucepan, heat 2 cups chocolate chips, the cream cheese and milk over low heat, stirring constantly, until chips are melted and mixture is smooth. Cool while making crust.
2In medium bowl, mix Bisquick mix, sugar and cocoa. Cut in butter, using pastry blender (or pulling 2 table knives through ingredients in opposite directions), until mixture is crumbly. Press half of the crumbly mixture (2 cups) on bottom of ungreased 13x9-inch pan. Sprinkle with white vanilla baking chips. Spoon chocolate mixture over crumbly mixture and chips; spread evenly. Sprinkle with remaining crumbly mixture and 1 cup chocolate chips. Press lightly with fork.
3Bake 30 to 35 minutes until center is set. Cool completely, about 1 hour. Refrigerate 1 hour or until chilled. For bars, cut into 8 rows by 6 rows. Store covered in refrigerator.