Add the flour, salt, and baking powder into a bowl, mix, and set aside.
In another bowl, add the softened (room temperature) butter, eggs. sugar, and vanilla. Beat with an electric mixer until smooth -- about a minute.
In three or four batches, add the dry ingredients to the wet, mixing until incorporated.
Roll them into one inch balls or roll the dough out using a rolling pin and cut out shapes using a cookie cutter. Top them with sprinkles, sanding sugar, cinnamon and sugar, or anything else you can think of. Place on a Silpat.
Bake at 350 degrees for 8-10 minutes. I take them out when there just starts to be the slightest hint of browning along the bottom.
Notes
For easy cleanup, line your baking sheet with parchment or a silpat.