Preheat the oven to 325°F (160°C). Grease a 9-inch springform pan and wrap the base with foil.

In a bowl, mix chocolate cookie crumbs, sugar, and melted butter. Press this mixture firmly into the bottom of the pan. Bake for 10 minutes, then set aside to cool.

In another bowl, beat the softened cream cheese and sugar until smooth. Add cocoa powder, then sour cream. Mix in eggs one at a time, then add vanilla and melted chocolate. Mix until well combined.

Pour the filling over the crust, smoothing it on top. Bake for 55–65 minutes, until the center is slightly wobbly. Let it cool in the oven with the door cracked for 1 hour, then chill in the refrigerator for at least 4 hours.

To make the topping, cook evaporated milk, brown sugar, egg yolks, and butter in a saucepan over medium heat until thickened, about 8–10 minutes. Stir in vanilla, coconut, and pecans. Let it cool slightly.

Spread the topping over the chilled cheesecake. Garnish with extra pecans or a drizzle of chocolate before serving.

Serve the German Chocolate Cheesecake chilled. Cut it into slices and enjoy on its own or with a dollop of whipped cream on the side.