Step 1

For the chocolate wafers:

Step 2

In a large bowl, whisk together the flour, cocoa powder, salt and baking powder. Set aside.

Step 3

In the bowl of a stand mixer fitted with the paddle attachment or in a medium bowl using a handheld mixer, cream the butter, granulated sugar and dark brown sugar on medium-high speed until smooth and fluffy, about 3 minutes.

Step 4

Add the egg, milk and vanilla and mix on low speed until just incorporated.

Step 5

With the mixer on low speed, add the flour mixture in 1-cup increments and mix until the flour is well-combined and a soft dough forms.

Step 6

Place the dough on the counter and knead it a couple of times using your hands. Roll the dough into a 2-inch-thick log and wrap in plastic wrap or parchment paper, twisting the ends to seal. Chill in the refrigerator for at least 30 minutes and up to overnight, until the dough is solid and easy to slice with a knife (this is also the point where the dough can be frozen for up to a month, if desired).

Step 7

When ready to bake, preheat the oven to 350 F and line two baking sheets with parchment paper. Slice the chilled dough crosswise into 1/4-inch-thick rounds and place them 1 inch apart on the prepared baking sheets (if you can't fit all the wafers on the baking sheets at once, you can bake them in batches).

Step 8

Bake for 8 to 10 minutes, until the wafers are set and appear dry. Allow to cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely until crisp. Store in an airtight container at room temperature for up to 4 days.

Step 9

For the cake:

Step 10

Line a 9- by 5-inch loaf pan with plastic wrap, leaving a 6-inch overhang on both long sides to act as handles.

Step 11

In the bowl of a stand mixer fitted with the paddle attachment or in a large bowl using a handheld mixer, beat the cream cheese until smooth. Add the powdered sugar and cocoa powder and beat until fully incorporated, light and smooth.

Step 12

Switch the paddle attachment out for the whisk attachment. Add the heavy cream to the cream cheese mixture and beat on low speed until there are no lumps, then increase the speed to medium and whip to soft peaks.

Step 13

Place a single layer of chocolate wafers on the bottom of the prepared loaf pan, breaking any additional wafers in half to fill in the extra space. Spread a generous 1/2 cup of the chocolate whipped cream over them. Repeat this process four more times to make a total of five layers, finishing with the whipped cream.

Step 14

Bring up the overhanging plastic wrap on the sides of the pan and cover the cake. Chill in the refrigerator for at least 12 hours and ideally up to 24 hours, until the wafers have softened to a cake-like texture.

Step 15

When ready to serve, unwrap the cake and turn it out of the pan onto a platter. Remove the pan and plastic wrap. Gently press the pecans against the sides of the cake. Slice into 1-inch-thick pieces and serve. Store leftover cake in an airtight container or wrapped in plastic wrap in the refrigerator for up to 3 days.