1. PREPARE THE OREO CRUST: Preheat the oven to 320°F. Grease and line an 8-inch springform pan with parchment paper. Blend the Oreo cookies in a food processor until they become fine, uniform crumbs — or seal them in a zip-top bag and crush thoroughly with a rolling pin. Add the melted butter and mix until the crumbs clump together when pressed. Press the mixture firmly into the bottom of the pan and 2 inches up the sides. Refrigerate while you make the filling.

2. MELT THE CHOCOLATE: Place the chopped dark chocolate in a microwave-safe bowl. Microwave in 30-second intervals, stirring well after each one, until completely smooth — typically 4–5 intervals. Set aside to cool for 5–10 minutes before using.

3. MAKE THE CHOCOLATE CHEESECAKE FILLING: Beat the softened cream cheese and sugar together on medium speed until completely smooth and creamy, about 2–3 minutes. Add the vanilla, then the eggs one at a time, mixing just until each egg incorporates — do not overbeat. Add the sour cream and salt and mix briefly until combined. Use a rubber spatula to fold the cooled melted chocolate through the batter until fully uniform with no white streaks remaining.

4. BAKE THE CHEESECAKE: Pour the chocolate filling into the chilled Oreo crust and smooth the top evenly. Place the pan on the middle oven rack and bake for 45–50 minutes — the cheesecake is done when the edges look set about 2 inches in and the center still has a gentle wobble when you nudge the pan. Do not bake until the center is fully firm.

5. COOL AND CHILL: Remove the cheesecake from the oven and let it cool in the pan at room temperature for at least 45 minutes. Cover loosely and refrigerate for at least 6 hours — overnight produces the best texture and makes slicing effortless.

6. MAKE THE FRESH CHERRY SAUCE: Combine the halved cherries, 2 tablespoons water, lemon juice, and sugar in a medium saucepan. Bring to a boil over medium heat, then reduce to a gentle simmer. Stir occasionally for about 10 minutes until the cherries soften and the liquid thickens. Mix the cornstarch with the extra tablespoon of water until smooth, then slowly drizzle the slurry into the simmering cherry mixture while stirring constantly. Remove from heat and let the sauce cool completely before using.

7. DECORATE AND SERVE: Whip the heavy cream to stiff peaks and pipe a border around the edge of the chilled cheesecake. Pour the cooled cherry sauce into the center of the whipped cream border. Release the springform ring, slice with a hot clean knife, and serve immediately.