In a large saucepan, whisk together egg yolks, evaporated milk, and vanilla extract until well combined. Cook over medium heat, stirring constantly, until mixture thickens, about 12-15 minutes. Remove from heat and stir in shredded coconut and toasted pecans. Pour into a heat-proof bowl and chill completely.

Preheat oven to 325°F. In a small bowl, combine Oreo crumbs and melted butter. Press mixture into the bottom of a 9-inch springform pan. Bake crust for 8-10 minutes, then cool.

Reduce oven temperature to 300°F. In a large bowl, beat cream cheese, sugar, flour, and cocoa powder until smooth. Mix in sour cream and vanilla. Incorporate melted German chocolate, then eggs one at a time, mixing slowly after each addition. Pour batter over the crust.

Drop spoonfuls of coconut pecan topping evenly over the batter. Gently add remaining batter. Cover the springform with foil and bake in a water bath for 1 hour 25 minutes. Turn off oven, crack door, and cool for 30 minutes. Refrigerate until fully set.

Remove cheesecake from springform, top with additional coconut pecan topping if desired, and drizzle with chocolate ganache. Serve chilled.