Prepare the raspberry mixture by combining 1 1/2 cups of fresh raspberries with heavy cream, mascarpone cheese, powdered sugar, and vanilla extract. Beat until smooth and fluffy.

Make the mascarpone cream by ensuring the mixture is well-blended and fluffy. Optionally whip the heavy cream separately and fold it into the mascarpone mixture for a lighter texture.

Assemble the tiramisu by mixing brewed coffee and coffee liqueur. Dip ladyfingers quickly in the coffee mixture and layer them in a baking dish. Spread half of the mascarpone mixture over the ladyfingers, then repeat with another layer of soaked ladyfingers and remaining mascarpone mixture. Top with remaining raspberries.

Chill the assembled tiramisu in the refrigerator for at least 4 hours or overnight. Dust with cocoa powder before serving.