12oz3 sticks of unsalted butter, at room temperature
¾cuplight brown sugarpacked
Preheat oven to 350 degrees F.
Line 2 (½ cup-12 capacity) muffin tins with cupcake papers.
In a small saucepan, heat the buttermilk until it just simmers.
Remove from heat and add the vanilla pod. Set aside.
In a medium bowl, blend the flour, baking powder, salt and baking soda. Set aside.
In a large bowl, on the high speed of an electric mixer, cream the butter and sugar until smooth.
Add the eggs and egg yolks, 1 at a time, beating well after each addition.
Cut the vanilla bean open and scrape out the seeds into the buttermilk. HERE is a video with instructions on how to open the vanilla pod
Add the vanilla to the buttermilk and mix well with a whisk.
Add the flour mixture in 3 parts, alternating with the buttermilk. With each addition, beat until the ingredients are incorporated but do not over beat.
Using an ice cream scoop or a spoon add the batter into the cupcake liners, filling them about ¾ full. Bake for 20 to 25 minutes, or until a cake tester inserted into the center of the cupcake comes out clean.
Cookie Dough Frosting
In a bowl, using the paddle attachment on high speed, beat the butter and brown sugar until smooth and fluffy.
Add the confectioners’ sugar and beat until smooth.
Add the salt and half of the flour and beat until combined. Add the other half of the flour and beat until combined.
Mix in the milk and vanilla extract until smooth and combined.