Pistachio Mascarpone Tiramisu with Coffee-Soaked Ladyfingers

Method

1. Prepare the pistachio butter up to a week ahead (or use store-bought).
2. Separate the eggs. In a large bowl, beat the egg whites with 1/4 cup (50g) of the sugar at medium-high speed until stiff peaks form, about 4 minutes. Set aside.
3. In another large bowl, whip the egg yolks with the remaining 1/4 cup (50g) sugar at medium-high speed until tripled in volume and pale yellow, about 4 minutes.
4. Add the mascarpone to the yolk mixture and beat at medium-low speed until smooth, 1–2 minutes. Then add the pistachio butter, vanilla, and almond extract; mix until well combined, about 1 minute.
5. Gently fold the beaten egg whites into the mascarpone mixture using a rubber spatula, taking care not to deflate the air.
6. Pour the coffee into a wide, shallow dish. If using, stir in the amaretto. Quickly dip half of the ladyfingers (one at a time) into the coffee, about 1/2 second per side, and arrange them in a single layer in a 9x9-inch pan.
7. Spread half of the mascarpone cream evenly over the ladyfingers.
8. Dip the remaining ladyfingers in the coffee and place them on top of the cream. Spread the rest of the mascarpone cream over the second layer.
9. Cover the pan and refrigerate for at least 6 hours, preferably overnight.
10. Just before serving, sprinkle the chopped pistachios over the top. Slice and serve cold.