Mix together flour, baking soda, and salt and set aside.
With an electric mixer, beat together butter and both sugars for 5 minutes.
To the sugar and butter mixture, add in the egg and vanilla. Mix for one additional minute.
Mix in the flour mixture until uniformly combined.
Use a spoon or cookie scoop to shape small balls about 2 tablespoons each. Arrange 2 inches apart on prepared cookie sheet (do not press down or shape the cookies).
Bake 8 minutes, or until the edges are just slightly gold. To preserve the chewy yumminess of this cookie do not bake too long (if you think they look just a bit under-done in the middle – then they are just right)!
Let cool on pan 5 minutes before transferring to a cooling rack.
These cookies might become slightly crisp initially, but will become soft and chewy once again if stored in an airtight container. These cookies are amazing dipped in a hot cup of coffee!