In a large mixing bowl add the confectioners sugar and vanilla to the heavy cream and beat with an electric mixer until stiff peaks form. Add 1/4 of the whipped cream to the custard cream and fold until well combined. Set aside.
In a bowl combine the espresso coffee and milk and mix to combine.
Dip each lady finger cookie into the coffee mixture and lay them into a 9x13 pan (I used a glass Pyrex) break the cookies to fit them in if necessary. I did two rows of 6 cookies vertically and two rows of 2 cookies horizontally, but just make sure the cookies fit nicely together.
Spoon 1/2 of the whipped cream over the first layer of cookies.
Add the second layer of cookies and spoon all of the custard mixed with whipped cream over them.
Add the third layer of cookies and cover with the remaining whipped cream.
Dust with the unsweetened cocoa powder as desired and decorate with the cream puffs.
Refrigerate for at least 4 hours or overnight. Serve chilled.