Preheat oven to 325°F. Prepare the crust: combine Oreo crumbs and melted butter, then press into a 9-inch springform pan. Bake for 8-10 minutes and set aside to cool.

Make the topping: whisk egg yolks, evaporated milk, and vanilla in a saucepan over medium heat until combined. Add sugar and butter, cook for 12-15 minutes until thickened, then stir in shredded coconut and pecans. Cool completely.

Beat cream cheese, sugar, and cocoa powder until smooth. Add sour cream and vanilla, then melted chocolate. Mix in eggs one at a time. Pour into prepared crust.

Drop spoonfuls of coconut pecan topping over the filling and gently swirl. Cover with foil and bake in a water bath at 300°F for 1 hour 25 minutes. Turn off oven, crack door, and cool cheesecake inside oven for 30 minutes. Refrigerate until firm.

Remove from oven, decorate with remaining topping, and drizzle with chocolate ganache. Chill before serving.