Step 1: Prepare the Crust

1. Preheat your oven to 325°F (165°C). Grease a 9-inch springform pan and line the bottom with parchment paper for easy removal.
2. In a mixing bowl, combine the chocolate cookie crumbs, melted butter, and sugar. Stir until the mixture resembles wet sand.
3. Press the mixture evenly into the bottom of the prepared pan, using the bottom of a glass to pack it tightly.
4. Bake the crust for 8-10 minutes, then remove it from the oven and let it cool while you prepare the filling.

Step 2: Make the Chocolate Cheesecake Filling

1. In a large mixing bowl, beat the cream cheese and sugar together with a hand mixer or stand mixer fitted with a paddle attachment until smooth and creamy, about 2-3 minutes.
2. Add the vanilla extract and mix to combine.
3. Beat in the eggs one at a time, ensuring each egg is fully incorporated before adding the next.
4. Stir in the sour cream or Greek yogurt until smooth.
5. Fold in the melted chocolate using a spatula, mixing gently until fully incorporated and the batter is uniform in color.

Step 3: Assemble and Bake

1. Pour the chocolate cheesecake filling over the cooled crust, smoothing the top with a spatula.
2. Place the springform pan on a baking sheet to catch any drips and bake for 55-60 minutes. The edges should be set, but the center should still have a slight jiggle when gently shaken.
3. Turn off the oven, crack the oven door slightly, and let the cheesecake cool inside for 1 hour. This gradual cooling process helps prevent cracks.

Step 4: Prepare the Strawberry Topping

1. In a medium saucepan, combine the strawberries, sugar, and lemon juice. Cook over medium heat for 5-7 minutes, stirring occasionally, until the strawberries release their juices.
2. In a small bowl, whisk together the cornstarch and water to make a slurry. Add the slurry to the strawberry mixture and stir until the sauce thickens, about 1-2 minutes.
3. Remove from heat and let the topping cool to room temperature.

Step 5: Assemble the Cheesecake

1. Once the cheesecake has cooled in the oven, transfer it to the refrigerator and chill for at least 4 hours or overnight.
2. When ready to serve, spread the strawberry topping evenly over the surface of the cheesecake. For a more elegant presentation, arrange the strawberries in a decorative pattern and drizzle the sauce on top.

Step 6: Serve and Enjoy

1. Carefully release the cheesecake from the springform pan and transfer it to a serving platter.
2. Slice with a sharp knife, wiping the blade clean between cuts for neat slices. Serve chilled and enjoy!