In a bowl, stir together 1.5 cups room-temperature espresso with 3 tablespoons rum. Pound green cardamoms using a mortar and pestle. Separate cardamom skins and throw them into the coffee and let them soak. Set aside ground cardamoms seeds for later.

In a glass bowl, whisk together eggs yolks and sugar. Place over steam on a saucepan of simmering water making sure the bottom of the bowl is not touching the water. Continue to whisk for 10 minutes on low heat until the mixture is pale, slightly thickened and no longer grainy. Take it off the heat and let cool slightly.

Whisk together mascarpone with 3 tablespoons rum. Next, beat in the warm yolk mixture until well incorporated.

In a separate bowl, using an electric mixer, beat cold heavy whipping cream until medium-stiff peaks form. Do not under-mix or over-mix.

Using a spatula, gently fold in half of the whipped cream, saffron and ground cardamom seeds into the mascarpone cream followed by the rest of the whipped cream, until incorporated. Do not overfold or it may become grainy.

Quickly dip half of the ladyfingers, one at a time in cooled expresso mix and arrange in a single layer at the bottom of a 9X13” casserole dish. Make sure not to over-soak the ladyfingers to prevent the cake from going soggy and collapsing.

Spread half of the cream mixture over the first layer of ladyfingers. Dip the rest of the ladyfingers, one at a time, and arrange on top of the first layer of cream. Spread remaining cream. Grate dark chocolate all over. Alternatively, you can sprinkle cocoa powder before serving the cake in step 8.

Cover and refrigerate overnight or for at least 6 hours to stiffen the cake. Cut into squares before serving chilled.