Whisk all the dry ingredients together and set aside.
2 cups All-purpose flour, 1 teaspoon Baking soda, 1 teaspoon Baking powder, ¼ teaspoon Salt
Set your mixer on paddle attachment, and beat the butter with two sugars well. This should take good 3-4 minutes.
1 cup Butter, 1 cup Brown sugar, packed, 1 cup Granulated sugar
Add the vanilla extract, then add the egg yolks, one at a time, and mix after each one.
1 tablespoon Vanilla extract, 5 Egg yolks
Add the mixed dry ingredients to the above mixture, and mix until incorporated. DO NOT OVERMIX.
Cover the dough and chill for 15 minutes. in the meantime, line two large baking sheets with parchment paper, and preheat the oven to 350°F.
Scoop out the cookie dough into a small ball, the size of a small tangerine. place on the lined baking sheets. leave 2-inch space between them.
Bake in the preheated oven, for 10-12 minutes. Until the edges are slightly brown and set. Let cool down on the baking sheet, then transfer to the cooling rack.