Step 1

Line a rimmed baking sheet with a silicone baking mat. Set aside.

Step 2

In your stand mixer*, beat cold butter, brown sugar, and granulated sugar until fluffy, about 2 minutes.

Step 3

Scrape down the sides of the bowl.

Step 4

Beat in egg yolk and vanilla.

Step 5

Beat in flour, cornstarch, baking powder, baking soda, and salt.

Step 6

Beat in chocolate chips/chunks.

Step 7

Use a cookie scoop to scoop the dough into 6 cookie dough balls.

Step 8

Optional - roll each cookie dough ball in granulated sugar.

Step 9

Place onto the prepared baking sheet.

Step 10

Optional, but recommended: refrigerate for 30 minutes.

Step 11

Preheat oven to 375 degrees F and bake for 8-10 minutes.

Step 12

Remove from oven and let cool on the baking sheet for 5 minutes.

Step 13

Transfer to a wire cooling rack to continue cooling or serve!