• Mix the coffee and the sugar and set aside to cool to room temperature.

Make the filling

• Place the egg yolks, sugar, and orange zest in a medium bowl and set over a double boiler.
• Constantly stir until the sugar has mostly dissolved. Remove from the heat and stir for about 3 minutes to cool the mixture.
• Mix in 1/2 cup of orange curd. Set aside.
• Using an electric mixer or a stand mixer, mix the mascarpone cheese until smooth, about 1 minute.
• Pour the heavy cream into the cheese and whip until medium peaks form. Do not over-mix, or else the cheese will curdle.
• Fold the yolk mixture into the cheese mixture until smooth.

Assembling

• Pour the coffee into a shallow-rimmed bowl and dip the bottom of each cookie into the coffee.
• Line the cookies in a single layer over an eight-inch baking dish.
• Top with half of the filling and spread over the cookies.
• Sprinkle the chopped chocolate.
• Repeat this with the rest of the cookies and filling creating a second layer.
• Spread half a cup of orange curd over the filling and refrigerate for at least four hours or overnight.
• Before serving, whip the heavy cream with the sugar until stiff peaks form.
• Use a pastry bag to pipe the cream over the Tiramisu, and dust with cocoa powder or shaved chocolate.