Preheat the oven to 350 F (180 C).
Line baking sheets with parchment paper. Set aside.
In a stand mixer or electric mixer, mix the butter with the brown sugar and sugar.
Combine the vanilla, egg, and egg yolk, beating until the mixture is pale and creamy.
Gently incorporate the flour and baking soda, mixing well, then add the chocolate chips.
Using an ice cream scoop or 1/4 cup (60 ml) measuring cup, scoop the dough and place it on the prepared baking sheets, spacing the cookies 2 inches (5 cm) apart.
Gently flatten the dough, then bake for 15 to 17 minutes or until the edges are lightly golden.
Let cool for 5 minutes on the baking sheets before transferring to a wire rack.