In a mixing bowl cream the butter with an electric mixer
Sift together the corn starch, powdered sugar and flour - yes I hate sifting as much as the next but it will be worth it.
Add the sifted mixture a little at a time to the creamed butter as the mixer is running on low.
Add the Princess flavoring
Once all is combined add the sprinkles and mix on low for just enough time to incorporate them.
Pull the dough together, wrap in plastic wrap and put in the refrigerator for about 30 minutes.
On a parchment paper-lined cookie sheet place about 1 inch balls of dough spaced out, with the bottom of a glass give each dough ball a light press to flatten.
Bake in a pre-heated 350° oven for 7-9 minutes.
Serve as is or allow to cool, drizzle with icing and add more sprinkles.