In a medium-size bowl, add the flour, baking soda and salt. Mix and set aside.
In a large bowl, whisk the butter, granulated sugar, and brown sugar until all is mixed well.
Add in the egg and vanilla and whisk some more, but make sure not to over whisk the egg.
Combine the dry ingredients and wet ingredients.
Fold in the chocolate chips with a spatula.
With a small ice cream scoop or cookie scoop, scoop the cookie dough on a lightly sprayed baking tray. Make sure to give the cookies space because they will spread out.
Bake the cookies for about 10 minutes, or until light brown. Then let them cool off for 3-5 minutes on the cookie tray and then place them on a wired rack to cool off completely for at least 20 minutes.
Notes
If you don't have parchment paper, then grease your sheet pan well with non-stick cooking spray or butter. However, if you know that your cookie sheet tends to make cookies stick then you will likely have more success with parchment paper.
A key to make softer cookies is to not over-mix the cookie dough. This baking process isn't difficult, but make sure you don't over mix the dough and don't over-bake the cookies. As a general rule, ingredients should be mixed until just combined.
Use room temperature butter in the wet ingredients so that it more easily incorporates with everything else.