First, prepare the berry gelée. In a small saucepan, add the berries, lime juice, half the water, and sugar. Bring to a boil for a few minutes. Mix the remaining water with the cornstarch until smooth, then pour it into the berry mixture. Stir over low heat until the mixture thickens. Remove from heat and let cool.

Meanwhile, prepare the mascarpone cream. Soak the gelatin in water for 10 minutes. Warm a little of the cream, then add the softened, squeezed gelatin. Stir until the gelatin is completely dissolved, then add it to the rest of the cream. In a glass bowl, combine the mascarpone, powdered sugar, and lime juice. Beat briefly with a mixer, then gradually add the cream, continuing to beat until the mixture is thick and smooth.