Add egg and vanilla and mix until creamy and smooth.
Mix, flour, baking soda, and salt into a separate bowl. Then add to wet mixture
Bake at 350° for 10 to 15 minutes.
Makes 15-20 cookies.
Tip: For fluffy cookies, press dough into a flat square wrapped in plastic wrap and put into the freezer for 20 minutes (while the oven preheats). When you are ready to bake, cut them into 1 inch squares.