Home­made Oreos

Makes about 18 2-1/2 inch sand­wich cook­ies
Recipe from Flour reprint­ed with per­mis­sion from Chron­i­cle Books.

In a medi­um bowl, whisk togeth­er the but­ter and sugar until well com­bined. Whisk in the vanil­la and choco­late. Whisk in the egg until com­bined.
In anoth­er bowl, whisk flour, cocoa, salt and soda until com­bined. Stir flour mix­ture into the choco­late mix­ture. Mix with your hands if it helps to com­bine the two. Let the dough sit for an hour to firm up.
Trans­fer the dough to a sheet of wax paper. Shape into a log about 2 1/2 inch­es in diam­e­ter. Place log along the edge of wax paper and roll. Shape as you roll to main­tain a smooth cylin­der. Twist ends of paper to secure and help keep the shape com­pact. Refrig­er­ate at least two hours or until firm. If log set­tles and flat­tens on one side, rotate every 15 min­utes or so to main­tain a round shape.
Heat oven to 325 degrees and line bak­ing sheet with parch­ment paper.
Cut dough in quar­ter inch thick slices and place on pre­pared bak­ing sheet. Bake for about 20 min­utes or until cook­ies are firm to the touch. Note: I under baked mine (almost half the time) and they were still great. Just watch them because it’s hard to tell by looks if they are done since they are so dark to begin with. These baked in batch­es well, so bake a few to test if you have time. And if your cook­ies are small­er, adjust the bak­ing time.
Cool and pre­pare the fill­ing. In a mixer, beat the but­ter until smooth and creamy. Add sugar and vanil­la and beat until smooth. Add milk and salt and con­tin­ue beat­ing until smooth again. Place about a table­spoon of fill­ing on the bot­tom of one cook­ie and sand­wich with a sec­ond. Repeat with remain­ing cook­ies and eat em up.