Preheat the oven to 325°F (163°C). Line two baking sheets with parchment paper.
In a medium bowl, whisk together the all-purpose flour, baking soda, and salt. Set aside.
In a large bowl, combine the melted unsalted butter, light brown sugar, and granulated sugar. Stir until well combined and smooth.
Add the vanilla extract, egg, and egg yolk to the butter and sugar mixture. Beat until the mixture is light and creamy, about 2 minutes.
Gradually add the dry flour mixture to the wet ingredients, stirring until just combined. Do not overmix.
Fold in the semisweet chocolate chips evenly throughout the dough.
Using a cookie scoop or tablespoon, drop dough balls about 2 inches apart onto the prepared baking sheets.
Bake in the preheated oven for 11 to 13 minutes, or until the edges are set but the centers still look slightly underbaked.
Remove from the oven and allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.