Brown the butter: In a small saucepan, over medium heat, melt and brown the butter for about 5 minutes. Bring it to a simmer while stirring constantly until the butter clears and light brown specks form. This will take about 10 minutes. Remove from heat and continue to stir until the bubbling stops. Allow the butter to cool completely for a few hours or overnight, before assembling the cookie dough.
Prep: Get the oven preheating to 350°F. Then line 3 cookie sheets with parchment paper and set aside.
Dough: In a large bowl, cream the butter & both sugars with an electric mixer until fluffy, this takes about 2 minutes. Add in the eggs, egg whites and vanilla extract. Mix until combined.
In a separate bowl, whisk together the flour, salt, and baking soda. Add the dry ingredients into the butter mixture in 2 batches. Stir well.
Fold in the chocolate chips & chocolate chunks.
Bake: Use a medium cookie (1.5 TBSP) to scoop the dough and roll into balls. Combine the remaining chocolate chips & chunks in a small bowl and press the top of each ball of dough into the chocolate chips. Place the cookie dough with the chocolate side up on the prepared baking sheets.
Bake for 8-10 minutes or until they are golden brown on edges. Let the cookies rest on the cookie sheet for 3-4 minutes before transferring them to a cooling rack. Serve slightly warm and enjoy!