Grind the biscuits and mix them with the melted butter. Mix well, lay it out and press the mixture with a spoon along the bottom of a cake form with a ring, laid out with baking paper. Put the cake form in the fridge for about 1/2 an hour.
Separately, beat the cream with the sugar. To it, add the cream cheese, juice of 1/2 a lemon, the finely grated lemon rinds and vanilla sugar, beat it into a cream with a mixer. Add the eggs 1 by 1, while stirring nonstop until you obtain a homogeneous mixture.
Smear the base of the cheesecake with part of the jam, pour the cream on top of it and even it out. Tip: wrap the outside of the cake form with aluminum foil to make sure water doesn't seep in while baking in a water bath.
Mix the rest of the jam with a little red confectionery dye and water, to make a kind of syrup. Fill an icing piping syringe with the syrup and spray it out in a spiral on top of the cream. Use a toothpick to smear the spiral (all in the same direction) into heart shapes all along the spiral.
Bake in a water bath in a preheated oven at 392°F (200 °C) for the first 15 min. and at 212°F (100 °C) for 1 hour. Place the cooled cheesecake in a suitable serving plate.