Place a greased 9-in. springform pan on a double thickness of heavy-duty foil (about 18 in. square). Securely wrap foil around pan.
In a large bowl, combine the crushed oreo cookies and butter. Press onto the bottom and 1-in. up the sides of prepared pan.
In a large bowl, beat the cream cheese, sugar, sour cream, melted chocolate, cocoa, cream and flour until smooth. Add eggs; beat on low speed just until combined. Stir in the espresso powder and vanilla. Pour into crust. Place springform pan in a large baking pan; add 1 in. of hot water to larger pan.
Bake at 350° for 60-70 minutes or until center is just set and top appears dull. Remove springform pan from water bath. Cool on a wire rack for 10 minutes. Carefully run a knife around edge of pan to loosen; cool 1 hour longer. Refrigerate overnight. Remove sides of pan.
Combine raspberries, sugar, water, and lemon juice in a saucepan over medium heat; cook and stir until raspberries break down, sugar dissolves, and sauce is heated through, 3 to 7 minutes. Remove from heat and press sauce through a fine-mesh strainer to remove seeds. Cool to room temperature, cover the bowl with plastic wrap, and refrigerate until chilled, at least 45 minutes.
Drizzle cheesecake with raspberry sauce and serve.