In a mixing bowl, combine mascarpone cheese, heavy cream, sugar, and vanilla extract. Whisk on medium-high speed for 3–5 minutes until smooth and fluffy.

Pour cooled brewed coffee into a shallow dish and add coffee liqueur if desired. Quickly dip each ladyfinger into the coffee, turning to soak, about 2 seconds per side.

Arrange half of the soaked ladyfingers in an even layer in a serving dish to cover the base completely.

Spread half of the whipped mascarpone mixture over the ladyfingers, smoothing it evenly with a spatula.

Repeat by placing another layer of soaked ladyfingers on top, followed by the remaining cream mixture, creating a two-layer dessert.

Sprinkle crushed pistachios over the final cream layer for garnish.

Cover with plastic wrap and refrigerate for at least 4–6 hours or overnight for best flavor development.