Preheat oven to 325°F (165°C). Wrap outside of a 9-inch springform pan tightly in two layers of foil. Process Oreos to fine crumbs, mix with melted butter and salt, press firmly into the pan base. Bake 8 minutes and cool.

Cook raspberries, sugar, and lemon juice in a small saucepan for 4 to 5 minutes until broken down. Strain through a fine mesh sieve. Cool completely.

Melt dark chocolate until smooth. Cool until barely warm.

Beat cream cheese on medium for 3 to 4 minutes until completely smooth. Add sugar and beat 2 minutes. Add eggs one at a time on low speed. Mix in sour cream, vanilla, cocoa, and salt. Fold in cooled melted chocolate until uniform.

Pour filling over crust. Drop raspberry puree by spoonfuls over the surface and swirl with a toothpick in loose figure-eights.

Place springform pan in a large roasting pan. Add hot water to reach 1 inch up the sides. Bake for 55 to 65 minutes until edges are set and center has a gentle wobble.

Turn off oven, crack door, and leave cheesecake inside for 1 hour. Remove and cool completely at room temperature. Refrigerate for at least 6 hours or overnight.

Heat cream until simmering. Pour over chopped chocolate. Rest 2 minutes then whisk until smooth. Cool 5 minutes until slightly thickened.

Pour ganache over chilled cheesecake. Top with fresh raspberries and chocolate curls. Slice with a warm clean knife and serve.