Sift together flour, baking soda and baking powder. Set aside. Mix butter and sugars together. Add in egg and vanilla. Mix in flour mixture in three equal parts until combined. Using an ice cream scoop, drop scoops of dough on parchment-lined baking sheet. (It's best to chill dough for about 30 minutes before baking.)
Bake 10 to 12 minutes at 350 degrees, or until edges turn golden. (Ovens vary, so watch your time.) Once baked, leave on cookie sheets for a few minutes, before cooling on wire racks. Decorate as desired.
***You can also use a smaller cookie scoop if desired. Please make sure to leave enough space between cookies for spreading.