-
1
Toss together the flour, baking soda, cornstarch and salt into a large bowl and set aside.
-
2
In a medium bowl, whisk together the melted butter, brown sugar and granulated sugar together until no brown sugar clumps remain. Whisk in the egg and the egg yolk, followed by the vanilla extract.
-
3
Pour wet ingredients into the dry ingredients and mix together with a large spoon or rubber spatula. The dough will be very soft and thick.
-
4
Fold in the chocolate chunks or chips. The melted butter may make it slightly difficult for the chunks to stick, just keep kneading them in until they are evenly dispersed throughout the dough.
-
5
Cover the dough, and let it chill in the refrigerator for 2 hours or up to 3 days. Chilling is mandatory.
-
6
Take the dough out of the fridge and allow to slightly soften at room temperature for about 10 minutes
-
7
Preheat the oven to 325 degrees Fahrenheit. Line two large baking sheets with parchment paper or silicone baking mats and set aside.
-
8
Roll the dough into balls, about 3 tablespoons of dough each. The dough will be a bit crumbly, but rolling them in your hands will help the dough to stay intact. Make sure you roll them taller rather than wider, this will ensure the cookies to be thick when they bake.
-
9
Put 8 balls of dough onto each cookie sheet. Press a few more chocolate chunks on top of the dough, if desired.
-
10
Bake the cookies for about 11-12 minutes. Once done, the cookies will look soft and a but under-baked, but they will continue to bake on the cookie sheets.
-
11
Allow them to cool for about 10 minutes before moving them to a wire rack to cool completely
-
12
When they are no longer hot to the touch, serve and enjoy!
