Preheat the oven to 350°F (177°C). Line a large baking sheet with parchment paper or a silicone baking mat and set aside.
Cream, emulsify, and build the dough
In a medium-sized mixing bowl using an electric mixer, beat the butter, brown sugar, and granulated sugar together for 1 to 2 minutes or until well combined.
Mix in the egg yolk and vanilla extract until fully combined, stopping to scrape down the sides of the bowl as needed.
Add the flour, baking soda, and salt and mix until just combined. Then, mix in the semi-sweet chocolate chips on low-speed until fully incorporated into the cookie dough.
Chill, scoop, and bake
Cover tightly and transfer to the freezer to chill for 10 minutes.
Using a 1.5 tablespoon cookie scoop, scoop the cookie dough onto the prepared baking sheet, making sure to leave a little room between each one.
Bake for 10 to 12 minutes or until the edges of the cookies are lightly golden brown and the tops are set. The centers should look slightly underdone.
Cool for the best texture
Remove the cookies from the oven and allow to cool on the baking sheet for 5 to 10 minutes, then transfer the cookies to a wire rack to cool completely.
Notes
For thicker and even more flavorful cookies, don't skip the 10-minute chill in the freezer and avoid overmixing after adding the flour.Nutrition information is estimated based on common ingredients and serving sizes and may vary.