Preheat oven to 350 degrees.
Grease and flour two round 8 or 9 inch baking pans.
Combine dry ingredients in the bowl of an electric mixer.
Add butter, milk and vanilla.
Turn speed to low and mix for about one minute.
Scrape bowl.
Add egg whites.
Turn speed to medium and beat about 1 more minutes or until smooth and fluffy.
Using a rubber spatula, gently fold in the sprinkles.
Pour batter into the prepared pans, as evenly as possible.
Bake at 350 degrees for 30-35 minutes or until toothpick inserted in the center comes out clean.
Cool 10 minutes.
Remove from pan and allow to cool completely on wired racks.
Frost, if desired.