
To start, combine the whipping cream and the sweetened condensed milk in the bowl of a stand mixer. With the whisk attachment, whip the cream on medium-high speed until soft peaks form, for roughly 3-5 minutes.
Meanwhile, brew the coffee and pour into a wide bowl or dish to cool down slightly.
Dip the cookies into the coffee and line them up on the bottom of an 8 by 12 casserole dish. See step-by-step photos for how to lay them out. Spread 1/3 of the cream mixture over top. Repeat the layering process two more times, ending with the last 1/3 of the cream mixture. You will have 3 layers of cookies and 3 layers of the cream. Cover tightly with plastic wrap and refrigerate for 7 hours or overnight.
Before serving, dust generously with cocoa powder, then cut into pieces and serve chilled.