Position a rack in the middle of the oven. Preheat the oven to 350º F (180º C). Line a cookie sheet with parchment paper or a silicone baking mat.
Using an electric hand mixer or a stand mixer, beat butter on medium speed for 2 - 3 minutes, or until creamy and pale in color. Add brown sugar and continue beating for 2 -3 minutes, until creamy and fluffy. Beat in vanilla; beat to until combine.
Reduce speed to low speed, add the flour and salt; beat until just incorporated. If the dough looks grainy, don't worry, turn off the mixer, and put the dough together with your hands until uniform and smooth.
Form 12 tablespoon-sized balls and slightly flatten with your hand. Alternatively, you can use a cookie stamp to flatten them.
Place them in the prepared cookie sheet and bake for 10-12 minutes or until the edges are lightly browned.
Cool on the pan for 2-3 minutes before transferring to a wire rack to cool completely.