2. For crust: Combine cookie crumbs and butter. Press mixture firmly over bottom of a 9 inch springform pan.

3. For Truffle mixture, melt chocolate chips in small saucepan over very low heat, stirring until smooth. Remove from heat after chocolate melts. Beat cream cheese in small bowl until fluffy. Gradually beat in raspberry preserves and melted chocolate; set aside.

4. For Filling, beat cream cheese in large mixer bowl until fluffy; beat in sour cream and sugar. Add eggs and vanilla; mix well. Pour into prepared pan. Drop truffle mixture by spoonfuls over top of filling, being careful not to swirl mixture. Bake until set, 1 1/4 to 1 1/2 hours. Cool completely on wire rack.

5. For Glaze, melt chocolate chips with cream over very low heat; stir until smooth. Spread over top of cheesecake; let some drizzle over side. Refrigerate until thoroughly chilled, several hours or overnight.

6. If desired, just before serving garnish with dollops of whipped cream and fresh raspberries.