Preheat oven to 200 C Line a 24cm round baking tin with pastry. Prick the base with a fork. Lay a sheet of baking parchment on top and top with baking beans. Bake in preheated oven for 20 minutes. Remove the beans and baking parchment and let cool.
Make the custard. Place milk, custard powder, 2 tablespoons sugar and vanilla extract into a pan, stir until smooth and gently heat until thick. Set aside to cool slightly.
Spread jam over pastry case and sprinkle with half the coconut. Pour in custard, sprinkle with coconut and remaining sugar. Chill until ready to serve.