Baked char siu bun with pineapple topping.

I have not made Chinese buns for a while now. Since I have some char siu sitting in the fridge I thought of making some char siu buns. I love the sweet crunchy topping on some of the buns in the chinese bakery called 'bo lo bau' or bun with a pineapple shape topping, though many have no added pineapple at all just the shape of the topping scored in diamond like this . I found this recipe with