Add butter and sugar to a standing mixer bowl. Whip on high speed until lighter in color and texture.
Stir in the egg yolks and vanilla until combined
Add the flour, cornflakes, and salt. Mix on low until just combined.
Cover the dough and chill for at least 3 hours in the fridge.
When you are ready to bake, preheat your oven to 350 degrees.
While the oven is preheating bring the cookie dough out and let it sit for about 15 minutes so that it is soft enough to scoop.
Scoop the cookie dough onto light metal cookie sheets lined with parchment paper.
Bake the cookies for 12-14 minutes until lightly golden brown on top.
Remove the cookies from the oven and allow them to sit on the pan for 5-10 minutes to set. Then, remove the cookies and allow them to cool fully. Enjoy!