Stir together the cookie crumbs, melted butter, pecans, and coconut in a bowl until the mixture is well combined. Press into the bottom of a 9x13-inch baking dish, and refrigerate while making filling.
Beat cream cheese, sugar, and custard powder in a large bowl with an electric mixer until light and fluffy, and beat in eggs, 1 at a time, beating each until fully incorporated before adding the next. Layer the filling over the crust.
Bake in the preheated oven until the center is almost set, about 40 minutes. Refrigerate the cheesecake until fully cold, at least 3 hours.
Melt the semisweet chocolate in a saucepan over very low heat with the cream, and stir until the mixture is smooth and well blended. Pour the chocolate mixture over the cheesecake, spread with a spatula to cover the middle layer, and refrigerate until the topping is firm, 15 to 20 minutes. Serve cold. Store leftovers in refrigerator.
