Beat heavy whipping cream with an electric mixer in a chilled bowl until soft peaks form. Beat confectioners' sugar, chocolate milk powder, and espresso powder into the whipped cream until the color is consistent and you again have soft peaks.
Pour coffee into a wide, shallow bowl. Dip graham crackers briefly in the coffee and layer into the bottom of a loaf pan in a single layer to cover the bottom. Spread about 1/4 of the whipping cream mixture over the crackers. Repeat layering with remaining ingredients to get four layers each of the cream and the cookies.
Cover loaf pan with plastic wrap and refrigerate until chilled, at least 2 hours.