cream the softened butter for about 1 minute

add sugar on medium until fluffy and light in color

mix in egg and vanilla

whisk together the flour, salt, baking powder, baking soda, and cream of tartar and then add slowly to bowl

add sprinkles (mix by hand)

make small ball doughs on cookie sheet and cool in fridge for at least 2 hours and up to 48 hours in the fridge