Mix crushed wafers and butter. Press into the bottom of a 9-inch springform pan. Set aside.

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.

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.

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.

Prepare, bake, and thoroughly cool the cheesecake. Cover tightly with plastic wrap. Store in the refrigerator up to 24 hours ahead.