Preheat your oven to 375°F (190°C). Line two large baking sheets with parchment paper and set aside.

In a medium bowl, whisk together flour, baking soda, and salt. Set this dry mixture aside. Pro tip: Whisking the dry ingredients ensures even distribution of leavening agents

In a large mixing bowl, combine the melted butter, brown sugar, and granulated sugar. Whisk until well combined and smooth. Pro tip: Make sure butter isn't too hot or it will cook the eggs in the next step

Add the whole egg, egg yolk, and vanilla extract. Whisk vigorously until the mixture is smooth and well combined. Pro tip: The extra egg yolk is key to achieving that perfectly chewy texture

Add the flour mixture to the wet ingredients and stir with a wooden spoon until just combined. Don't overmix. Pro tip: Overmixing develops gluten, which can make cookies tough

Fold in the chocolate chips until evenly distributed throughout the dough. Pro tip: Reserve a few extra chocolate chips to press on top of each cookie for a bakery-style look

Using a cookie scoop or tablespoon, portion the dough into 2-tablespoon sized balls. Place them 2 inches apart on the prepared baking sheets. Pro tip: Slightly underbaked cookies will continue cooking on the hot pan, so don't overbake

Bake for 9-11 minutes, or until the edges are golden brown but the centers still look slightly underbaked. Pro tip: The cookies will look soft and puffy when done – they'll flatten as they cool

Remove from oven and let cookies cool on the baking sheet for 5 minutes before transferring to a wire rack. Pro tip: This resting time helps the cookies set up properly without breaking