Homemade Oreos

I found these on Smitten Kitchen, but it looks like they maybe came from this book: Retro Desserts, Wayne Brachman

I made these as a tester batch to see if they were good enough to serve on our wedding cookie bar. I took them to a Memorial Day BBQ, and someone I never met before said he would leave his wife and baby for these cookies. Well, I don't know about that, but these were darn good. Even my Foodie-with-a-capital-F supervisor said they were "perfect," which she does not dole out readily. At any rate, they ended up being the talk of the party, and I'm guessing I will be asked to make these again.

Makes 25 to 30 sandwich cookies

For the chocolate wafers:
1 ¼ cups all-purpose flour
½ cup unsweetened Dutch process cocoa
1 teaspoon baking soda
¼ teaspoon baking powder
¼ teaspoon salt
1 to 1 ½ cups sugar*
½ cup plus 2 tablespoons (1 ¼ sticks) room-temperature, unsalted butter
1 large egg

For the filling:
¼ cup (½ stick) room-temperature, unsalted butter
¼ cup vegetable shortening
2 cups sifted confectioners’ sugar
2 teaspoons vanilla extract

1. Set two racks in the middle of the oven. Preheat to 375 degrees.
2. In a food processor, or bowl of an electric mixer, thoroughly mix the flour, cocoa, baking soda and powder, salt, and sugar. While pulsing, or on low speed, add the butter, and then the egg. Continue processing or mixing until dough comes together in a mass.
3. Take rounded teaspoons of batter and place on a parchment paper-lined baking sheet approximately 2 inches apart. With moistened hands, slightly flatten the dough. Bake for 9 minutes, rotating once for even baking. Set baking sheets on a rack to cool.
4. To make the cream, place butter and shortening in a mixing bowl, and at low speed, gradually beat in the sugar and vanilla. Turn the mixer on high and beat for 2-3 minutes until filling is light and fluffy.
5. To assemble the cookies, in a pastry bag with a 1/2 inch, round tip, pipe teaspoon-size blobs of cream into the center of one cookie. Place another cookie, equal in size to the first, on top of the cream. Lightly press, to work the filling evenly to the outsides of the cookie. Continue this process until all the cookies have been sandwiched with cream. Dunk generously in a large glass of milk.

* Smitten Kitchen's notes: This is a sweet cookie. A good, sweet cookie. Yet, if you think of an actual Oreos, the wafers are fairly un-sweet and actually on the slightly salty side, which contrasts with the super-sweetness of the filling bringing harmony, happiness, yada yada. If you want your cookie closer to that original, you can take out a full half-cup of the sugar. I usually do. If you want to make the cookie by itself (as I did a while back for ice cream sandwiches), go ahead and use the full amount.