Preheat oven to 325°F; line two baking sheets with parchment or silicone mats.
Whisk flour, baking soda, and salt in a bowl; set aside.
Beat butter and both sugars in a large bowl on medium about 3 minutes, until creamy and smooth.
Beat in whole egg and yolks one at a time, beating well after each; mix in vanilla.
Reduce to low; gradually mix in flour mixture just until no dry streaks remain.
Fold in dark chocolate chips evenly with a rubber spatula.
Scoop 2-tablespoon portions onto prepared sheets, 2 inches apart.
Bake 13-14 minutes, until edges are set and lightly golden but centers very soft and underbaked.
Cool on sheet 8-10 minutes; carefully transfer to a wire rack to cool completely.