Preheat the oven to 175°C top/bottom heat and line the base of a 23 cm springform pan with parchment paper.

Mix the crushed Oreo cookies with the melted butter, press the mixture firmly into the bottom of the pan, and bake the crust for 8 minutes.

Beat the cream cheese and sugar until smooth, then mix in the cocoa powder, melted chocolate, sour cream, and vanilla.

Add the eggs one at a time, mixing just until combined after each addition to keep the batter dense and smooth.

Pour the filling over the crust and smooth the surface with a spatula.

Bake the cheesecake for 60 to 65 minutes, until the edges are set and the center still has a slight wobble.

Cool the cheesecake at room temperature for 1 hour, then chill it for at least 6 hours or overnight before adding the topping.

For the topping, cook the evaporated milk, brown sugar, butter, and egg yolks over medium heat for 8 to 10 minutes, stirring constantly until thickened.

Stir in the coconut and pecans, cool the topping until warm, then spread it over the chilled cheesecake before slicing.