Preheat oven to 375°
Using a medium mixing bowl, whisk flour, Hershey's® Cocoa, baking soda and salt together, set aside.
In a large bowl, beat butter and sugar, brown sugar together until creamy.
Beat vanilla and corn syrup then add eggs into mixture and beat until creamy.
Gradually add flour mixture into sugar mixture and combined.
Stir chocolate chips, chocolate chunks, chopped walnuts into cookie mixture.
Using a 1"cookie scoop, or by rounded teaspoon, drop onto ungreased baking sheet and bake for 8-10 minutes or until edges just start to brown.
Remove from oven and place on wire rack to cool.