Step #2 Line a 14-inch, light colored, round pizza pan with parchment paper & grease the parchment paper.
Step #3 In a large bowl, cream the butter & sugars.
Step #4 Add the eggs, beating well after the addition of each.
Step #5 In a bowl, baking soda, mix the flour, & salt & mix with a whisk.
Step #6 Add to the butter mixture, mixing to incorporate.
Step #7 Add the vanilla extract.
Step #8 Fold in the dark & white chips & the nuts.
Step #9 Spread across the bottom of the prepared pan & bake this until the edges are golden & the cookie is set but the center is still slightly soft, 20 to 25 mins.
Step #10 Cool in the pan for 10 mins, then transfer to a wire rack to cool completely.
Step #11 To serve, sift confectioners sugar & sweetened cocoa over the top, & cut into wedges.
Step #12 Serve sweetened whipped cream on the side.