Preheat the oven to 350 degrees F and line two cookie sheets with parchment paper.
Microwave the butter for about 40 seconds to just barely melt it. It shouldn’t be hot – but it should be almost entirely liquid. Cool for a minute or two until room temperature.
10 tablespoons unsalted butter
Whisk together the flour, baking soda and salt in a medium bowl.
2 cups unbleached all-purpose flour, ½ teaspoon baking soda, ½ teaspoon fine sea salt
Combine the granulated sugar, brown sugar, and melted butter in the bowl of a stand mixer fitted with the paddle attachment. Beat on medium speed for 2 minutes until well blended.
½ cup granulated sugar, ⅔ cup light brown sugar
Beat in the egg, egg yolk and vanilla until light and creamy.
1 large egg, 1 large egg yolk, 1 tablespoon pure vanilla extract
Beat in the flour mixture on low until just combined.
Remove bowl from the mixer and fold in the chocolate chips.
1 ½ cups semi-sweet chocolate chips
Use a 2oz/1/4 cup cream scoop to scoop out the dough onto the prepared cookie sheets, leaving 3" between each cookie. Refrigerate for 30 minutes or for up to two days.
Bake for 14-16 minutes or until the edges are lightly brown and the tops look just set. Transfer to cookie sheets to wire racks to cool slightly. Serve warm.