Preheat oven to 350 degrees.
Spray a 13 x 9 inch pan with nonstick cooking spray.
Cut cookie dough in half crosswise.
Cut each section in half lengthwise.
With floured fingers, press dough in bottom of sprayed pan to form crust.
Bake for 10 minutes.
Remove crust from oven.
Meanwhile, in a medium bowl combine milk, peanut butter, vanilla and egg yolks; mix until smooth.
Spoon evenly over partially baked crust.
Return to oven and bake 20 to 25 minutes, or until set.
Remove from oven.
Sprinkle with chocolate chips and let stand 3 minutes to soften, then spread chocolate evenly over top.
Cool 1 1/2 hours or until completely cooled.
Refrigerate 30 minutes to set chocolate.
Cut into bars.