Birthday Cake & White Chocolate Sprinkle Cookies

1 (15.25 ounce) box White Cake mix
1/4 cup all-purpose flour
1 teaspoon baking powder
1/2 teaspoon salt
2 eggs
1/3 cup vegetable oil
1/2 teaspoon vanilla
zest of one lemon
3/4 cup rainbow sprinkles
1 cup white chocolate chips
additional rainbow sprinkles to roll cookies in (optional)
Preheat oven to 350 degrees F. 
In a large bowl add the cake mix, flour, baking powder and salt.  Whisk to combine.
In a medium sized bowl, combine the eggs, oil, vanilla, and lemon zest. Mix well.
Add the egg mixture to the dry ingredients and mix well to combine.  The batter will seem difficult to combine but keep mixing using a rubber spatula and it will get there.  It will feel rather glutenous.
Use a wooden spoon to mix in the white chocolate chips and sprinkles.  Roll into 1.5 inch balls.  If desired, roll balls in additional rainbow sprinkles, coating evenly.  Place balls on an ungreased cookies sheet two inches apart and bake for 10 minutes.
Remove from oven and allow to cool on the pan for 5 minutes.  Using a spatula, remove cookies from pan and allow to finish cooling on a wire rack.  Store in an airtight container for up to 3 days.