Adapted from Eric on Just Desserts
3 sticks butter
1 cup sugar
2 cups very firmly packed brown sugar
4 2/3 cups flour
1 tablespoon baking soda
1 1/4 teaspoons salt (use a bit more if using unsalted butter)
2 egg yolks
22 ounces chocolate wafers or good quality chocolate cut into chunks
Preheat oven to 325º. Line cookie sheets with parchment.
Melt butter and allow to cool slightly. Using stand mixer with paddle attachment, mix sugars and melted butter. Add eggs and yolks slowly and mix to combine. You can also do this with a hand mixer or with a wooden spoon...just don't overbeat.
Whisk together dry ingredients. Add flour mixture and mix till just combined. Stir in chocolate. You may want to refrigerate dough before baking...I did just briefly.
I used my 1/4 cup cookie scoop to make large rounds of dough. You could easily do this by hand. Bake 14-16 minutes till just golden brown. Make approximately 24 large cookies