1. Mix crushed wafers and butter. Press into the bottom of a 9-inch springform pan. Set aside.
2. Meanwhile, in a small saucepan combine pureed raspberries, liqueur or sugar, and cornstarch, stirring well. Cook and stir over medium heat until thickened and bubbly. Cook and stir 2 minutes more. Set aside to cool. Meanwhile, melt chocolate over low heat, stirring frequently. Set aside to cool.
3. In a large bowl beat cream cheese and 1/2 cup sugar with electric mixer on medium speed until well blended. Add eggs, 1 at a time, beating just until combined after each addition. Gradually beat in melted white chocolate until blended. Spread over crumb crust. Spoon 1/2 cup of raspberry mixture over filling; swirl with a knife to marbleize. Cover and chill remaining raspberry sauce; return to room temperature before serving.
4. Bake in a 350 degree F oven for 35 to 40 minutes or until center appears set when shaken. (Do not overbake.) Cool 15 minutes on a wire rack. Loosen crust from sides of pan. Cool 30 minutes more; remove sides of pan. Cool completely. Chill at least 4 hours before slicing. Serve with remaining raspberry mixture. Makes 12 to 16 servings.