Mom's Favorite Sugar Cookies

1 cup Butter (2 sticks)
1/2 cup White Sugar
1/2 cup Brown Sugar
1 egg
1 tsp vanilla
2 cups Flour
1/2 tsp Baking Soda
1/2 tsp Salt
Extra sugar for flattening cookie balls.

Preheat oven to 350º.

Cream together butter and sugars until smooth. Add egg and vanilla and blend to mixture is smooth. In a medium bowl mix flour, soda and salt. Gradually add flour mixture to butter mixture until smooth. Chill dough till cold. Form balls about 1 inch in diameter and place on cookie sheet fairly far apart (cookies tend to spread). Take a large water glass and dip it into extra sugar, flatten a dough ball with the glass, repeat for each remaining cookie.  Bake in a 350º oven until lightly browned 10-13 minutes.
Remove cookie sheets from oven and let cool for about 4 minutes, transfer to racks to finish cooling. Store in an airtight container once completely cool.