Combine milk, sugar and chips in a 4 cup glass measure. Cover at 100 percent for 3 minutes, stirring twice. Sift together cornstarch and cocoa powder. Stir in water to make a smooth mixture. Add to chocolate mixture. Whisk in egg and yolks. Cook for 2 minutes, stir well and cook for another 2 minutes. Pour mixture into food processor and add butter and vanilla. Process until smooth. Pour into four individual cups and chill.
Recipe Courtesy of Food Network Kitchens