Homemade Oreos

Let's get started!

1. Cookies: In a medium bowl, which the dry ingredients together.
2. In a stand mixer fitted with a paddle attachment, beat the butter and sugar until light and fluffy (3 to 5 minutes). Add the yolk and vanilla, then mix in the dry ingredients in three parts until combined.
3. Split the dough and shape into flat squares. Wrap tightly with plastic wrap and chill (2 to 3 hours).
4. Roll out the dough between 2 silicon mats to 1/8" thick. Cut out circles, and place them on a parchment lined baking sheet. Cover with plastic wrap and freeze for 30 minutes.
5. Preheat the oven to 350F°. 
6. Using a small paintbrush, dust the Oreo mold with flour. Press a chilled dough disk inside. Gently pop out the cookie and place it on a parchment lined baking sheet. Repeat with all cookies. 
7. Bake for 12-14 minutes. Flatten cookies lightly with and offset spatula when they are still warm. Let cool completely.
8. Filling: In a medium bowl, beat the butter and shortening until smooth. Add the vanilla and gradually add the powdered sugar. Scoop into a small piping bag. 
9. Pipe filling onto the center of half the cookies (about 1/8" thick), and gently flatten. Top with an unfrosted cookie and press together gently.