Line a 23 cm springform tin and lightly grease the sides.
Brew strong black coffee and let it cool completely.
Blend cookies and cocoa powder into fine crumbs, then mix with melted butter.
Press the crumb mixture firmly into the base of the tin and chill.
Beat cream cheese until smooth, then add mascarpone, powdered sugar, and vanilla and mix until creamy.
Pour in 360 g heavy cream and whip until the filling is thick and holds soft peaks.
Spread half the filling over the crust.
Dip ladyfingers briefly in cooled coffee (with Amaretto if using) and arrange in a single layer over the filling.
Spread the remaining filling on top, smooth the surface, and chill for at least 8 hours.
Whip 230 g heavy cream with powdered sugar and vanilla, spread or pipe over the set cheesecake, and dust with cocoa powder before serving.