Make the strong coffee in a bowl and add amaretto. Set aside to let it cool down.
In a medium bowl, blend mascarpone with 1/4 cup of heavy whipping cream until smooth using a whisk.
In another mixing bowl, blend 1 cup of heavy whipping cream with vanilla and brown sugar until soft peaks – about 3 minutes at medium speed.
Add the mascarpone to the mixing bowl and continue blending at slow speed for about a minute. Do not over blend!
Oil an 8-inch baking pan and line the sides with parchment paper.
Quickly dip each ladyfinger into the coffee and line up a layer in the baking pan. Cut the biscuits where necessary to completely cover the surface of the pan.
Spread half of the mascarpone cream over the biscuits to cover them completely. Spread the cream evenly.
Repeat the process with another layer of biscuits and then mascarpone cream, spreading it evenly.
Cover with plastic wrap and refrigerate for at least 3 hours or overnight.
Before serving, dust the top surface with the cocoa powder. Remove the springform side of the pan and the parchment paper.