Preheat the oven to 375 F and line a large baking sheet with parchment paper.
Soften the butter in the microwave in 10 second increments, until it’s about half melted and very soft.
Combine the butter with the sugars in the bowl of a stand mixer or in a mixing bowl with a hand mixer and cream for 3-4 minutes on medium speed or until the mixtures has become light and very fluffy.
Stir in the egg, egg yolk, and vanilla extract and mix the wet ingredients until well combined.
In a separate bowl for dry ingredients, mix the flour, baking soda, and salt.
Stir the dry ingredients into the wet ingredients by hand until completely combined.
Fold in the chocolate chunks and/or chips to the mixture.
Portion the cookie dough into 2 oz. balls.
Place them on the baking sheet with at least 3 inches between them.
Bake for 10-12 minutes, or until the edges are golden brown.
Remove from the oven and allow them to cool on the sheet for 5-10 minutes.
Remove the cookies to a cooling rack to cool completely.