Heat the oven to 325°F (163°C), lightly grease a 9-inch springform pan, and wrap the outside with foil if using a water bath.

Combine the cookie crumbs, melted butter, and optional salt. Press the mixture firmly over the bottom and slightly up the sides of the pan, then bake for 8–10 minutes and cool briefly.

Melt the chocolate gently in the microwave or over a double boiler. Set it aside until warm rather than hot.

Beat the softened cream cheese and sugar on low to medium speed until smooth. Mix in the cocoa powder and salt.

Add the melted chocolate, sour cream, and vanilla, mixing only until incorporated.

Add the eggs one at a time on low speed, mixing only until each egg disappears into the batter.

Pour the batter over the crust and bake at 325°F for approximately 60–75 minutes, until the edges are set and the center has a slight wobble.

Turn off the oven, crack the door, and leave the cheesecake inside for about 30 minutes. Remove it, cool completely at room temperature, and refrigerate for at least 6 hours, preferably overnight.

Spread the cherry pie filling over the chilled cheesecake shortly before serving, or prepare and cool the homemade cherry topping before spooning it over the cake.

For ganache, pour steaming heavy cream over chopped chocolate, wait 2 minutes, and stir until smooth. Cool slightly, then drizzle over the cheesecake or spread it on top before adding the cherries.