Preheat oven to 200 degrees celsius.
Mix flour, icing sugar, and butter until it forms a breadcrumb texture. Add milk and form a dough.
Roll out on a floured bench to a rectangle shape rough 30cm long.
Add cooled set custard on top and spoon on your kumquat jam. Mix slightly.
Then roll the long side to form a long roll. This is quite tricky but just do your best.
Then cut into 8cm pieces and place in a greased oven dish with the cut side down.
Spoon on any extra mixture that has fallen out. Bake for 20mins until golden.
Allow cooling before removing them so the custard has set again.
You can also brush with extra jam to glaze.