Use a hand held mixer or your kitchen aid with the whisk attachment and whip the heavy cream with 1 tablespoon of sugar until fluffy and on the stiff side. Cover and refrigerate.
Use the same whisk attachment and whip up the mascarpone cheese in a large bowl until smooth and creamy, a few minutes. Using a slotted spoon start adding the blueberries to the whipped mascarpone leaving as much of the juices behind as possible. Mix only until combined.
Add the whipped cream on top and using a spatula fold it into the cheese and berry filling. Take good care not to over mix this so the cake stays fluffy and creamy.
Place the spring form pan with the graham cracker crust on a serving plate then pour in the mascarpone cheese mixture inside. Spread it evenly and garnish with the fresh blackberries.
At this point you can pop it in the freezer for about 30 minutes to quickly set it, or refrigerate for a couple of hours or until set to your liking.
Before serving remove the spring form side and garnish with the lime slices all around the cake.
Garnish with a rose, lemon balm, or any edible flowers you like on top and enjoy!