Preheat your oven to 375°F (190°C).
In a bowl, mix together the flour, baking soda, and baking powder.
In a separate bowl, cream together the butter and sugar until smooth.
Beat in the egg and vanilla extract.
Gradually add the dry ingredients to the wet mixture.
Mix until fully combined; the dough should be soft.
Roll rounded teaspoonfuls of dough into balls.
Place the balls onto ungreased cookie sheets, spacing them apart.
Flatten each ball slightly with the bottom of a glass.
Bake for 8 to 10 minutes or until golden.
Allow cookies to cool on wire racks.