Preparation Steps

• In a heatproof bowl, whisk together the egg yolks and granulated sugar. Place the bowl over a saucepan of simmering water (bain-marie), ensuring the bottom of the bowl does not touch the water. Whisk continuously until the mixture thickens and reaches 160°F (71°C). Remove from heat and stir in the milk and pistachio paste until well combined. Let it cool completely.
• In a separate bowl, whip the heavy cream until stiff peaks form. In another bowl, beat the softened mascarpone cheese until smooth.
• Gently fold the whipped cream into the cooled pistachio mixture. Then, fold in the mascarpone cheese until the cream is smooth and uniform.
• In a shallow dish, combine the cooled brewed coffee and coffee liqueur (if using). Quickly dip each ladyfinger into the coffee mixture, ensuring they are coated but not soggy.
• Arrange a layer of dipped ladyfingers in the bottom of an 8x8 inch baking dish. Spread half of the pistachio cream mixture evenly over the ladyfingers.
• Repeat with another layer of dipped ladyfingers and the remaining pistachio cream mixture.
• Cover the dish with plastic wrap and refrigerate for at least 4 hours, or preferably overnight, to allow the flavors to meld and the tiramisu to set.
• Before serving, sprinkle the top generously with chopped pistachios and a dusting of powdered sugar.