Step 1

Lightly grease (or line with parchment) two baking sheets, or more if you have them; you'll make 3 to 4 baking sheets' worth of cookies.

Step 2

, To make the cookies: In a medium-sized bowl, beat together the sugar, butter, salt, baking powder, and espresso powder.

Step 3

, Beat in the egg and vanilla, then the flour and cocoas. Cover the dough and chill for 30 minutes. While the dough is chilling, preheat the oven to 350°F.

Step 4

, Roll the dough about 1/8" thick; use cocoa instead of flour to dust your rolling board and the dough.

Step 5

, Cut into 2 1/2"-round cookies. A biscuit cutter is handy for this.

Step 6

, Bake the cookies for 10 minutes. Watch them closely at the end of the baking time, and if you start to smell chocolate before 10 minutes has gone by, take them out. When they're done, remove the cookies from the oven, and allow them to cool completely.

Step 7

, To make the cream filling: In a large mixing bowl or the bowl of your stand mixer, combine the heavy cream, sugar, and vanilla extract. Whip the cream until stiff peaks form. Be sure not to overbeat — the cream will deflate and become dense.

Step 8

, Line a 9” x 5” loaf pan with plastic wrap so that there's a few inches of excess hanging over the edges on all sides.

Step 9

, Spread a 1/2” layer of whipped cream across the bottom of the pan.

Step 10

, Place eight wafers atop the cream, overlapping as necessary. Spread with a thin layer of cream, then place another eight cookies on top. Continue this layering  process until you've used all the cookies.

Step 11

, Cover the tops of the cookies with whipped cream, reserving any extra. Cover the pan and chill the cake for at least 4 hours, or overnight.

Step 12

, Turn the cake out of the pan to serve, spreading any remaining whipped cream on top.

Step 13

, Storage information: Store any leftover cake in the refrigerator, well-wrapped, for up to several days.