Homemade Oreos

In a bowl, whisk together the butter and sugar until well combined. Whisk in the vanilla and chocolate. Add the egg, and whisk until thoroughly incorporated.

In another bowl, stir together the flour, cocoa powder, salt and baking soda until well blended. Using a wooden spoon, stir the flour mixture into the chocolate mixture. The dough will start to seem too floury, and you might want to switch to using your hands until it comes together. It will have the consistency of Play-Doh. Let the dough sit at room temperature for about 1 hour to firm up.

Tear off a 15-inch-square sheet of parchment or waxed paper. Set the dough on it. Using your hands, shape the dough into a rough log about 10 inches long and 2 ½ inches in diameter. Place the log at the edge of the paper, and roll the paper around the log. With the log fully encased in the paper, roll it into a smoother log, keeping it 2 ½ inches in diameter. Refrigerate for at least 2 hours, or until firm. 

Position a rack in the middle of the oven, and preheat it to 325 degrees. Line a baking sheet with parchment paper. Cut the log into ¼-inch-thick slices. Place the slices about 1 inch apart on the baking sheet. You might want to pinch the edges a bit to remove any crumbles. Bake the cookies for 20 to 25 minutes, or until they are firm to the touch. As soon as they feel firm in the center when you poke them with your finger, remove them from the oven. You can’t judge by the color because they start out black. Cook the cookies on the baking sheet.

To make the filling, beat the butter on low speed for about 30 seconds in a stand mixer fitted with the paddle attachment. When the butter is smooth and soft, add the powdered sugar and vanilla, and beat until it is perfectly smooth. Add the milk and salt, and beat again. The filling will look like white spackle and feel like putty. You should have about 1 cup.

Scoop about 1 rounded tablespoon of filling onto the bottom of 1 cookie. Top with a second cookie, bottom-side down, then press the cookies together to spread the filling toward the edges. Repeat until all of the cookies are filled and sandwiched.

Store the assembled cookies in an airtight container in the freezer.