1-Add the butter to a medium sauce: Add the butter to a medium sauce pan and heat it over medium heat. Allow the butter to melt and come to a simmer. Simmer until the butter is foamy, giving off a nutty scent and has browned. The whole process should take about 10 minutes. Remove the butter from the heat and transfer it to a large bowl. Make sure to scrape the bottom of the pan to get all the brown bits.
2-Chill the brown butter: Chill the brown butter. To do this quickly, fill a larger bowl with ice and place the bowl with the brown butter on top of the ice filled bowl. Stir the brown butter as it cools. You’ll want it to be about the same consistency as very softened regular butter. You can also just refrigerate the brown butter until it is a similar consistency. The ice method is just a lot quicker.
3-Preheat the oven to 350 ℉ (175: Preheat the oven to 350 ℉ (175 ℃). Line two baking sheets with parchment paper and set aside.
4-In a medium bowl, whisk the flour,: In a medium bowl, whisk the flour, baking powder, baking soda, and salt together. Then set aside the flour mixture.
5-Whip the brown butter with an electric: Whip the brown butter with an electric mixer on medium high speed until it is light and fluffy.
6-To the bowl with the brown butter,: To the bowl with the brown butter, add in the brown sugar and granulated white sugar. Cream together with an electric mixer until pale in color and slightly fluffy. (It will not be the same consistency as regular creamed butter and sugar.)
7-Add in the egg, egg yolk, and: Add in the egg, egg yolk, and vanilla. Mix together on medium speed for two minutes, or until the mixture is pale in color and fluffy.
8-Add in the dry ingredients and mix: Add in the dry ingredients and mix on low speed just until combined, or fold in with a rubber spatula.
9-Add in the chocolate chunks and fold: Add in the chocolate chunks and fold into the dough with a rubber spatula.
10-Scoop the dough with a large, 2: Scoop the dough with a large, 2 tablespoon capacity cookie scoop, into 16 scoops. (I overfill my scoop to give me extra large cookies.) Chill the scooped cookie dough balls for 15 minutes, just to help firm up the dough a bit.
11-Arrange the balls of dough 2 inches: Arrange the balls of dough 2 inches apart on a parchment paper lined baking sheet; bake 6 cookies at a time. Bake for 10-11 minutes until a light golden brown. When the cookies are straight out of the oven, scoot a large circular cookie cutter around them to give them a perfect circular shape and thick center! (They will have spread a bit while baking.) Let the cookies cool on the cookie sheet for five minutes then transfer them to a wire rack to completely cool. While they’re cooling, add extra chocolate chunks on top of each cookie, and sprinkle on a little flaky sea salt.