Prep ahead: Make the vegan mascarpone, vegan ladyfingers, and pistachio cream up to 1-3 days ahead of time.
Pistachio mascarpone: Add the pistachio cream and dairy-free mascarpone to a high-speed blender or food processor and blitz for a couple of minutes until smooth and creamy. Place in the fridge.
Amaretto-soak: Combine the water and sugar in a saucepan and simmer over medium heat. Cook for around 5 minutes, until the sugar dissolves. Remove from the heat and whisk in the pistachio butter and amaretto.
Transfer the amaretto simple syrup to a shallow bowl or container and let it cool to room temperature.
Assemble: Add 4 tablespoons of the chilled pistachio mascarpone mixture to the bottom of your dish and spread in an even layer.
Quickly dunk half of the ladyfinger cookies into the amaretto mixture and arrange them in a single layer on top.
Pour half of the remaining mascarpone cream filling on top and spread it in an even layer using an offset spatula.
Follow with a second layer of dipped ladyfingers and the second half of the cream mixture. Smooth out the top with an offset spatula.
Chill: Place it in the fridge to chill and set for at least 2-4 hours, the longer it chills the more set it will become.
Serving: Once set, sprinkle ground pistachios on top of the tiramisu before serving.
Storage: Place it in a sealed container or wrap the baking dish with plastic wrap so that no part of the tiramisù is exposed to the air. Refrigerate for up to 3 days.
