01 - Preheat oven to 340°F. Grease a 9-inch springform pan and line the base with parchment paper.
02 - Mix crushed chocolate cookies, melted butter, sugar, and salt in a medium bowl. Press firmly into the bottom of the pan. Bake for 10 minutes, then let cool.
03 - Melt dark chocolate in a heatproof bowl over simmering water (double boiler); let cool slightly.
04 - Beat cream cheese and sugar until smooth. Add eggs one at a time, mixing well after each. Mix in sour cream, vanilla, flour, and salt until just combined. Fold in melted chocolate.
05 - Pour filling over the cooled crust, smoothing the top. Tap the pan gently to release air bubbles. Bake for 50-55 minutes, until edges are set but center is slightly jiggly.
06 - Turn off oven, crack the door, and let cheesecake cool inside for 1 hour. Remove from oven, run a knife around the edge, and cool to room temperature.
07 - Refrigerate at least 4 hours or overnight.
08 - Combine cherries, sugar, lemon juice, and water in a saucepan. Cook over medium heat until cherries release juices (about 5 minutes). Mix cornstarch with a little cold water, stir into cherries, and simmer until thickened (2-3 minutes). Cool completely.
09 - Spread cherry topping over the chilled cheesecake before serving.