In a large bowl, mix together the flour, sugar, instant yeast, and salt.
In another bowl, whisk together the warm coconut milk, melted butter, egg, and vanilla extract (if using).
Gradually add the wet ingredients to the dry ingredients, stirring until a dough forms.
Turn the dough out onto a lightly floured surface and knead for about 5-7 minutes, or until smooth and elastic.
Place the dough in a greased bowl, cover with a damp cloth or plastic wrap, and let it rise in a warm place for about 1 hour, or until doubled in size.
Punch down the dough and divide it into 12 equal pieces.
Shape each piece into a ball and place them in a greased baking dish, close together but not touching.
In a small saucepan, combine the coconut milk and sugar.
Heat over medium heat, stirring occasionally, until the sugar is dissolved. Do not let it boil.
Preheat your oven to 350째F (175째C).
Pour the coconut sauce evenly over the shaped dough balls.
Bake in the preheated oven for 25-30 minutes, or until the tops are golden brown and the buns are cooked through.
Allow the Panipopo to cool slightly before serving.
Enjoy your meal!