• Add the first amount of sugar to the hot coffee, stir until the sugar dissolves, then place the coffee in the refrigerator to chill while you make the filling.
• In a large bowl, whip the egg yolks and sugar until pale yellow.

  If you are nervous about consuming raw eggs, whip them over a double boiler, or use pasteurized eggs.
• Add the mascarpone cheese and mix just until incorporated and smooth.
• Pour in the heavy cream and mix until the cream has been incorporated and the mixture is slightly thick and smooth.
• Fold in the Blackberry curd.

Assembling

• Dip the bottom of each ladyfinger cookie into the coffee and arrange the cookies in a single layer over an eight-inch (or nine-inch) springform pan.
• Dollop half of the mascarpone filling and use an offset spatula to spread it evenly.
• Sprinkle the chopped chocolate over the filling, then do the same with the sliced blackberries.
• Repeat with the remaining ladyfingers and the mascarpone filling.
• Refrigerate for four hours, or preferably overnight.
• Right before serving, dust the top of the tiramisu with unsweetened cocoa powder and serve.