In a large mixing bowl, cream sugar and butter together. Add egg yolks and vanilla. Beat again.


Add flour, baking soda, and cream of tartar. Beat again.
 Form dough into tablespoon size balls and flatten them gently.

Place them in an air fryer basket lined with parchment paper 2 inches apart. You will have to bake these in batches.

Air fry at 350ºF for 7 minutes or until golden brown and slightly cracked on top.

In a medium mixing bowl, cream butter and powdered sugar together. Add 2 tablespoons of milk and vanilla. Beat well.  If it is too thick, add more milk. If it is too thin, add more powdered sugar. Before icing cookies in the center, be sure to allow cookies to cool off completely.

Place sprinkles in a shallow bowl.

Make whoopie pies by filling two cookies with frosting.

Roll each whoopie pie in sprinkles to coat the edges.