01 - Using a hand mixer or whisk, beat the heavy cream with half of the granulated sugar in a mixing bowl until soft peaks form, about 2-3 minutes.
02 - In a separate bowl, whisk together the mascarpone cheese, remaining sugar, and vanilla extract until completely smooth and creamy.
03 - Gently fold the whipped cream into the mascarpone mixture using a spatula until fully incorporated and no white streaks remain.
04 - If using liqueur, place the fresh raspberries in a small bowl and toss gently with 2 tablespoons of raspberry liqueur to coat evenly.
05 - Working quickly, dip each ladyfinger into the cooled coffee just long enough to moisten—about 1 second per side—being careful not to oversaturate.
06 - Arrange half of the coffee-dipped ladyfingers in a single layer in the bottom of an 8x8 inch baking dish. Spread half of the mascarpone cream evenly over the ladyfingers, then distribute half of the raspberries across the cream.
07 - Repeat the layering process with the remaining ladyfingers, mascarpone cream, and raspberries, ensuring even distribution.
08 - Cover the dish with plastic wrap or foil and refrigerate for at least 4 hours, preferably overnight, to allow the ladyfingers to soften and flavors to meld.
09 - Just before serving, use a sifter to dust the top generously with powdered sugar. Garnish with additional fresh raspberries and mint leaves if desired. Serve cold.