1. **Prepare the Crust:** In a medium bowl, combine 1 ½ cups of crushed graham cracker crumbs with ¼ cup of granulated sugar. Pour in ½ cup of melted unsalted butter and mix thoroughly until the crumbs are evenly moistened. Press this mixture firmly into the bottom of a 9-inch springform pan to form an even layer. Use the bottom of a glass or your hand to ensure it's compact. Place the springform pan in the refrigerator while you prepare the filling.

2. **Make the Raspberry Sauce:** In a small saucepan over medium heat, combine 1 cup of fresh raspberries (or frozen, thawed) with 2 tablespoons of granulated sugar and 1 tablespoon of lemon juice. Bring to a simmer, stirring occasionally, until the raspberries break down and the sauce thickens slightly (about 5-7 minutes). If you prefer a smooth sauce, press it through a fine-mesh sieve to remove the seeds. Set aside to cool completely.

3. **Melt the White Chocolate:** In a heatproof bowl set over a saucepan of simmering water (bain-marie), or in the microwave in 30-second intervals, melt 8 ounces of good-quality white chocolate, stirring until smooth. Be careful not to overheat the white chocolate, as it can seize. Let it cool slightly, but keep it melted.

4. **Prepare the Cheesecake Filling:** In a large mixing bowl, using an electric mixer, beat 16 ounces of softened cream cheese on medium speed until smooth and creamy, about 2-3 minutes. Gradually add 1/2 cup of powdered sugar and 1 teaspoon of pure vanilla extract, continuing to beat until well combined and fluffy.

5. **Fold in Whipped Cream and White Chocolate:** In a separate, chilled bowl, whip 1 cup of cold heavy cream until soft peaks form. Gently fold the melted and slightly cooled white chocolate into the cream cheese mixture until just combined. Then, carefully fold in the whipped cream in two additions, using a spatula, until no streaks remain. Do not overmix, as this can deflate the whipped cream.

6. **Assemble the Cheesecake:** Pour the cheesecake filling over the chilled graham cracker crust in the springform pan. Use an offset spatula or the back of a spoon to smooth the top. Drizzle about half of the cooled raspberry sauce over the top of the cheesecake. Swirl it gently with a knife or skewer for a marbled effect, if desired.

7. **Chill and Serve:** Cover the springform pan loosely with plastic wrap and refrigerate for at least 4-6 hours, or preferably overnight, until the cheesecake is firm and set. Before serving, carefully remove the sides of the springform pan. Garnish with additional fresh raspberries and the remaining raspberry sauce.