Chocolate sandwich cookies

Instructions

1. Step 1

   Beat 140 g softened unsalted butter with 150 g granulated sugar for about three minutes, then add 50 g eggs and 4 g vanilla extract and beat until combined. Creaming the butter and sugar well gives the cookies a crisp, light snap instead of a hard bite. The mixture is ready when it is fluffy, smooth and paler than the butter was at the start.

   Suggested time: about 3 minutes.

   Mark step 1 as done

2. Step 2

   Sift 160 g all-purpose flour, 45 g cocoa powder, 2 g baking soda and 2 g salt into the butter mixture and mix on the lowest speed just until the dough comes together. Sifting removes lumps, since cocoa clumps very easily. The dough is ready when it is an even dark brown and forms a soft mass.

   Mark step 2 as done

3. Step 3

   Divide the dough in two, roll each portion between two sheets of parchment paper to about three millimeters thick, stack them on a flat tray and refrigerate for about an hour. Rolling before chilling gives you thin, even sheets of dough without dusting on extra flour. The dough is ready when it is firm and the paper peels off easily.

   Suggested time: about 60 minutes.

   Mark step 3 as done

4. Step 4

   Preheat the oven to 175 degrees Celsius and line a clean baking sheet with parchment paper. Chocolate cookies are hard to judge by color, so an oven at the right temperature helps you time them more accurately. The oven is ready after about fifteen minutes of preheating.

   Mark step 4 as done

5. Step 5

   Cut the cold dough with a round cutter about five centimeters across, place the rounds on the baking sheet two centimeters apart, then gather the scraps, roll them out again and chill before cutting more. Chilling the scraps again keeps the shapes as sharp as the first cut. You are done when you have an even number of identical rounds to pair up.

   Mark step 5 as done

6. Step 6

   Bake the cookies at 175 degrees Celsius for about 10 to 12 minutes. Because the cookies are already dark, rely on the surface and the aroma to tell when they are done. The cookies are ready when the tops are completely dry, have the faintest cracks and your kitchen smells of toasted cocoa.

   Bake at 175°C for about 10 to 12 minutes.

   Mark step 6 as done

7. Step 7

   Leave the cookies on the baking sheet for five minutes, then move them to a rack and let them cool completely for about thirty minutes. The cookies only turn crisp once cool, and the filling will melt right away if they are still warm. The cookies are ready when they feel firm and crisp and do not bend.

   Suggested time: about 30 minutes.

   Mark step 7 as done

8. Step 8

   Beat 70 g softened unsalted butter until smooth, gradually add 180 g powdered sugar, 3 g vanilla extract and 10 g whole milk, then beat for about three minutes. Beating longer makes the filling whiter and velvety smooth. The filling is ready when it is ivory white and thick enough to hold its shape when piped.

   Suggested time: about 3 minutes.

   Mark step 8 as done

9. Step 9

   Spoon the filling into a piping bag with a round tip, pipe a dot of filling onto the center of the underside of half the cookies, then top with the remaining cookies and twist gently to spread the filling. A gentle twist as you press spreads the filling evenly without pushing it out the sides. The cookies are finished when the filling is an even layer sitting neatly about two millimeters in from the edge.

   Mark step 9 as done