Preheat your oven to 250 C. Prepare a non-stick spring form (24 cm diameter) by brushing the base with some of the butter, then lining the base with non-stick alu foil or a baking sheet. Crush the digestive biscuits in a food processor until you have very fine crumbs. Combine with the remaining butter. Spread the biscuit mix on the bottom, pressing down to form an even layer. Bake the base in the oven for about 7 minutes or until it starts to brown. Leave to cool.
For the cream scrape the seeds out of the vanilla pod and put in a mixing bowl. Reserve the pod. Add the egg yolks, 60 g of the caster sugar, the mascarpone and philadelphia to the bowl and combine thoroughly. Beat the egg whites with 30 g of the sugar until stiff, then beat the cream until stiff. Add both to the cheese mix. Heat up the lime juice in a pan with the vanilla pod. When it starts to boil, discard the vanilla and stir in 2 sachets of the gelatine, removing from the heat and making sure it dissolves completely. You should end up with runny liquid, if you feel it's too sticky and solid add just a little bit of hot water. Add this to the cream cheese mix.
Prepare the peach topping. Peel the peaches by scoring their skins crosswise on the bottom, then submerging in simmering water for a minute. Lift and peel, then cut off the stone and transfer to a food processor to produce a fine purée. Mix in 40 g of the sugar, cook in a pan for 5 minutes and add the gelatine. Stir vigorously to dissolve and leave to cool down.
Now assemble the cake. Cut four of the peaches up, discarding the stone. Cut into segments and distribute evenly over the cake base. Spoon the cream mix on top and top with the cold peach purée.
Rest in the fridge for at least 2 hours until set.