Line a baking sheet with parchment paper.

In a medium bowl, whisk together the flour, baking soda and salt. Set aside.

In the bowl of a stand mixer fitted with a paddle attachment, beat together the stick of room temperature butter, granulated sugar, dark brown and light brown sugars on medium speed until combined, scraping down the sides of the bowl as needed. DO NOT OVER BEAT.

Beat in the eggs one at a time, then beat in the vanilla until combined.

Slowly stream in the melted butter until combined.

Reduce the mixer speed to low, add the flour mixture and beat until completely combined.

Stir in the chocolate chips or the other mix-in combinations you desire by hand.

Using a tablespoon or small scoop, scoop the cookie dough onto the prepared baking sheet and then chill in the refrigerator for 1 hour.

Preheat the oven to 375 degrees F. Line 2 baking sheets with parchment paper.

Place half of the cookie dough scoops 2 inches apart on the prepared baking sheets. Chill the remaining dough while you bake the first batch.

Bake until the cookies are golden around the edges but still soft in the middle, 8 to 10 minutes.

Let the cookies cool on the baking sheets for 2 minutes, then transfer them to a wire rack to cool completely, if you desire.

Cool the baking sheets completely, then line with parchment paper and repeat the baking process with the remaining dough.