Preheat the oven to 325 degrees F (165 degrees C). Grease and flour a 9 inch square pan.
In a medium bowl, stir together the vegetable oil, eggs, egg yolk, applesauce and chocolate syrup until well blended. Stir in the brownie mix and cocoa powder. Fold in the chocolate chips and walnuts. Spread evenly into the prepared pan.
Bake for 40 to 45 minutes in the preheated oven, until the top of the brownies appear dry.
