Sift the flour into a large bowl and make a well in the centre. Place the egg, sugar and half the milk in a jug and whisk to combine. Gradually add the egg mixture to the flour, stirring until combined. Add the butter and remaining milk. Whisk until smooth. Cover with plastic wrap. Set aside at room temperature for 30 mins to rest.
Meanwhile, place gelatine in a small bowl and cover with cold water. Place the custard in a saucepan over medium heat. Add chocolate and stir for 5 mins or until chocolate melts and mixture is smooth. Drain the gelatine and squeeze to remove excess liquid. Add to the custard mixture and stir until gelatine dissolves. Transfer to a heatproof bowl. Add coconut cream. Stir to combine. Cover with plastic wrap and place in the fridge for 1 hour or until almost set.
Lightly grease a 22cm non-stick frying pan and heat over medium heat. Stir the extra milk into the crepe batter. Pour ¼ cup of the batter into the pan, swirling to coat the base. Cook for 1-2 mins or until the crepe is dry on the surface and crisp around the edges. Transfer to a plate. Repeat with the remaining batter to make 20 crepes, stacking cooked crepes on the plate.
Grease the base of a 24cm (base measurement) springform pan and line with baking paper. Place 1 crepe in the base of prepared pan. Spoon over 1/4 cup of custard mixture and spread over the crepe, leaving a 1cm border. Place another crepe on top. Continue layering with the remaining custard mixture and crepes. Place in the fridge for 1 hour or until the cake is firm.
Carefully transfer the cake to a serving platter. Top with whipped cream, flaked coconut and passionfruit pulp. Cut into wedges to serve.