Cream butter and sugar together until fluffy.
Add egg and vanilla, mix.
Add flour, mixing thoroughly.
Scrape down sides of bowl and mix again.
Roll into 1-inch balls.
Dip top half of balls in reserved sugar.
Place on parchment lined cookie sheet two inches apart.
Bake in a preheated 375-degree oven for 8 to 10 minutes.
Cool for 5 minutes before removing from pan.
Remove to wire rack to finish cooling.