Beat together butter and sugars until light and fluffy.
Add egg and vanilla, beat well.
Add flour and salt, and stir well to thoroughly combine with the butter mixture, then stir in the chocolate chips.
Chill dough in a covered bowl in the refrigerator, for one hour.
Before baking, preheat oven to 375°.
Scoop dough into rounded tablespoonfuls, onto parchment lined baking sheets. For perfectly shaped cookies, flatten JUST slightly.
Bake for 7 minutes, or until cookies are lightly golden brown around the edges, and just set in the centers.
Remove from oven, and let rest on the baking sheets for 10 minutes before removing.
Cookies may be stored in a tighly-covered container in the refrigerator for up to 1 week.