• Preheat the oven to 350.
• Line baking sheets with parchment paper.
• In a large bowl, mix the dry ingredients for the cookies (flour, baking powder, baking soda and salt). In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugar until fluffy, about two minutes.
• Add the eggs and the yolk, one at a time and mix.
• Add the flour mixture in three parts, alternating with the buttermilk (begin and end with flour). Add the vanilla .
• Using a ¼ cup scoop, drop the dough on the prepared baking sheets or use a muffin top pan as I did.
• Bake for 17 minutes, baking each sheet one at a time. Edges should be lightly browned. Allow to cool completely before frosting.

Frosting, in a large bowl, whisk together the confectioners' sugar, milk, cream and vanilla. If the mixture is too thick, add milk by the teaspoon.

• Divide in half and color one half blue.
• Using a spatula, frost one half blueand allow to dry 20 mins. before frosting the other half with the white. Let the frosted cookies set for one hour before serving.