Get out and measure your ingredients.
Move the oven rack to lower-middle position and preheat oven to 325 degrees F. Line 2 baking trays with parchment paper and set aside.
Whisk together flour, baking soda, and salt in bowl.
Use a stand mixer with paddle attachment to beat melted butter with brown sugar and granulated sugar on medium speed, about 2 minutes.
When the mixture is smooth, add egg and yolk and vanilla and beat until combined.
Reduce speed of mixer to low and add ⅓ of flour mixture to bowl. Mix just until combined and scrape down bowl as needed. Repeat two times with remaining flour.
Use a spatula or wooden spoon and stir in chocolate chips by hand.
Roll 2 tablespoons of dough into balls and space them 2 inches apart on parchment-lined baking trays.
Bake cookies 1 tray at a time, until edges are set and beginning to brown but centers are still soft and puffy, about 15 to 20 minutes. Rotate baking tray halfway through bake time.
Let cookies cool on sheets for 10 minutes before placing on rack to finish cooling before serving.
Enjoy!
Dunk in milk if desired!
Enjoy every bite!