Mix the butter and sugars.
In a large bowl, beat the softened butter, brown sugar, and granulated sugar for about 1 minute, just until combined. Avoid beating until overly fluffy.
Add the egg and vanilla.
Mix in the egg and vanilla just until incorporated. Scrape down the sides of the bowl as needed.
Add the dry ingredients.
In a separate bowl, whisk together the flour, baking soda, and salt.
Add to the butter mixture and mix on low until about halfway combined. Fold in the chocolate chips, then gently finish mixing just until no dry flour remains.
Shape and chill.
Roll or scoop the dough into balls about 1 1/2–2 inches across. Place on a parchment-lined tray, cover, and refrigerate for 2 hours.
Preheat the oven.
Toward the end of the chilling time, preheat the oven to 350°F. Line baking sheets with parchment paper.
Bake.
Arrange the chilled dough balls about 3 inches apart on the prepared baking sheets.
Bake for 13–15 minutes, until the edges are lightly golden and the centers look just set but still soft. Larger cookies may need a little longer.
Cool and enjoy.
Let the cookies rest on the baking sheet for 5–10 minutes before transferring to a wire rack. Enjoy warm or allow to cool completely.