Combine chocolate wafer crumbs, sugar, and melted butter.

Press the mixture into the bottom of a 9-inch springform pan to form the crust.

Bake the crust at 325°F (163°C) for 10 minutes.

Let the crust cool completely.

In a large bowl, beat cream cheese, sugar, cocoa, and vanilla extract until smooth.

Add eggs one at a time, beating well after each addition.

Stir in evaporated milk.

Pour the cheesecake filling into the cooled crust.

Bake at 350°F (175°C) for 35 minutes.

Loosen the cheesecake from the pan's sides.

Let the cheesecake cool to room temperature.

Chill in the refrigerator for at least 8 hours.

In a saucepan, combine evaporated milk, sugar, butter, and egg.

Cook over medium heat, stirring constantly, for 7 minutes until thickened.

Stir in chopped pecans and flaked coconut.

Spread the topping evenly over the chilled cheesecake.

Serve chilled.