Begin by lining a 6-inch cake pan with parchment paper.
Next, take your ladyfingers and line them up vertically against the edges of the pan. Make sure to line the bottom of the pan as well.
Take your raspberries and place them in a blender. Blend until smooth.
In a large mixing bowl, add the mascarpone cheese, heavy cream, and granulated sugar. Mix until smooth and creamy.
Zest the lemon and add it to the bowl along with the vanilla extract.
Soak the gelatin sheets in a bowl of cold water for 5 minutes.
In a small saucepan, add the water and heat on medium heat. Squeeze any excess water from the gelatin sheets and add them to the saucepan. Whisk until the gelatin dissolves.
Take the gelatin mixture and pour it into the mascarpone mixture. Mix well.
Take half of the raspberry puree and mix it into the mascarpone mixture.
Pour the mascarpone mixture into the prepared cake pan. Spread it evenly and tap the pan lightly to remove any air bubbles.
Place the cake in the refrigerator and chill for at least 3 hours, or until set.
Once set, remove the cake from the refrigerator and take off the parchment paper.
Take the remaining raspberry puree and spread it over the top of the cake.
Garnish with fresh raspberries and serve chilled.