Prepare the pan. Line the base of a springform pan with parchment. Lightly grease the sides. This helps the cheesecake release cleanly.
Make the crust. Crush biscuits into fine crumbs. Stir in melted butter, ground almonds, sugar, and salt. The mixture should feel like damp sand and hold together when pressed.
Press and chill. Tip crumbs into the pan. Press firmly with the back of a spoon or a flat-bottomed glass, pushing slightly up the sides. Chill for 20 minutes to set.
Beat the cheeses. In a large bowl, beat cream cheese and mascarpone until smooth and lump-free, about 1–2 minutes. Don’t overbeat.
Add flavorings. Mix in icing sugar, almond extract, vanilla, lemon juice, and zest. Taste and adjust sugar or almond extract to your liking.
Whip the cream. In a separate bowl, whip cold double cream to soft peaks. It should hold shape but still be silky, not stiff.
Fold together. Gently fold the whipped cream into the cheese mixture in two additions. Keep it airy. You’re aiming for a thick, spreadable filling.
Assemble the filling. Spread half the filling over the chilled crust. Smooth the top. Dollop 2–3 tablespoons of cherry preserves in small blobs, then swirl lightly for a subtle ripple.
Add the rest. Top with the remaining filling and smooth the surface. Run a palette knife around the edge to remove air pockets.
Chill to set. Cover and refrigerate for at least 6 hours, ideally overnight. The longer chill gives cleaner slices.
Add the cherry layer. Stir the remaining cherry preserves to loosen. If using, mix in kirsch or amaretto. Spread a thin, even layer over the chilled cheesecake.
Finish and garnish. Arrange halved cherries on top. Sprinkle toasted flaked almonds for crunch. Chill 30 minutes more to let the topping settle.
Release and slice. Run a warm knife around the edge before unclipping the pan. Wipe the knife between slices for sharp edges.