Step 1: Prepare the Oven and Pan

1. Preheat your oven to 325°F (170°C).
2. Position the oven rack in the lower third of the oven.
3. Wrap the outside of a 9-inch springform pan with an oven bag or slow cooker liner to prevent water from leaking into the pan. Follow this by wrapping it with aluminum foil at least 3 times, ensuring all seams are tightly covered.

Step 2: Make the Oreo Crust

1. Crush the Oreos: Pulse the Oreo cookies (wafers and filling) in a food processor until they become fine crumbs. If you don’t have a food processor, you can place the cookies in a freezer bag and crush them using a rolling pin.
2. Mix with Butter: In a bowl, mix the Oreo crumbs with melted butter. If using a food processor, add the butter and pulse a few times until evenly combined.
3. Press into Pan: Press the mixture firmly into the bottom of the prepared springform pan, creating a slight edge around the sides.
4. Bake: Bake the crust in the preheated oven for 8 minutes, then remove from the oven. Leave the oven on for baking the cheesecake later.

Step 3: Prepare the White Chocolate Cheesecake Filling

1. Melt the White Chocolate: Chop the white chocolate into very small pieces and place them in a large, heat-proof bowl. Heat the heavy cream until it’s almost boiling (you can do this in the microwave using short intervals or on the stovetop using a double boiler). Pour the hot cream over the chocolate and let it sit for 2-3 minutes before whisking until smooth. If the chocolate hasn’t fully melted, microwave in 30-second intervals at medium power, whisking between each interval. Set aside.
2. Beat the Cream Cheese and Sugar: In a large bowl, beat the cream cheese and sugar together until smooth and creamy, making sure no lumps remain.
3. Incorporate the Eggs: In a separate bowl, lightly whisk the eggs, then slowly beat them into the cream cheese mixture in two additions. Be careful not to overmix.
4. Combine Chocolate and Cream Cheese Mixture: Carefully whisk the melted white chocolate mixture into the cream cheese mixture by hand, using a wire whisk to avoid overmixing.
5. Pour into Crust: Pour the cheesecake batter into the prepared crust and smooth the top with a spatula.

Step 4: Bake the Cheesecake

1. Water Bath: Place the springform pan into the center of a large roasting pan. Pour boiling water into the roasting pan, filling it about ½ to 1 inch deep.
2. Bake: Place the roasting pan into the oven and bake the cheesecake for about 50-60 minutes. The cheesecake is done when it wobbles like a bowl of pudding or jello when you gently shake the pan. If it moves like a glass of milk, it needs more time.
3. Cool: Once baked, remove the cheesecake from the oven and run a thin knife around the edges to prevent cracking as it cools. Let it cool in the water bath until it reaches room temperature, then transfer to the fridge to chill for at least 6 hours or, preferably, overnight.

Step 5: Make the Chocolate Ganache Topping

1. Melt the Semi-Sweet Chocolate: Chop the semi-sweet chocolate into small pieces and place them in a heat-proof bowl. Heat the cream until it’s almost boiling, then pour it over the chopped chocolate. Let it sit for 2 minutes, then whisk until smooth. If the chocolate hasn’t fully melted, microwave in 30-second intervals at medium power, whisking between each interval.
2. Top the Cheesecake: Remove the chilled cheesecake from the fridge. If there’s any condensation on the surface, gently blot it with a paper towel. Let the ganache cool slightly before pouring it over the cheesecake. Allow some of it to drip over the sides for a beautiful finish.
3. Melt White Chocolate: Chop the white chocolate and melt it in the microwave or using a double boiler. Drizzle the white chocolate over the top of the ganache.
4. Garnish: Optionally, place fresh raspberries around the edge of the cheesecake for added color and flavor.
5. Chill Again: Return the cheesecake to the fridge until ready to serve.

Step 6: Serve

When ready to serve, use a sharp, thin knife (not a table knife) to slice the cheesecake. Wipe the knife clean between cuts for the best results.