In a separate bowl, mix dry ingredients, milk powder, sugar and salt. Form a well in the center of the ingredients.
Slowly pour a third of activated yeast, at a time, with dry ingredients in the center of the well and mix. Mix well for 10 minutes.
Allow dough to rest for 5 minutes.
Add coconut oil, mix for 5 minutes.
Form a mound, cover and rest until it doubles in size (1½ to 2 hours).
Poke hole in center of dough to release gas, dough should not deflate.
On a floured surface, continue releasing the gas by kneading the dough.
Roll the dough to stretch, and cut into equal parts. 8 for big boa, 10 or 12 for smaller size baos.
Cover cut pieces with plastic wrap to keep from drying out.
Roll out a pieces in a circle shape, be sure to leave a little thickness in the center.
With floured hands, place dough in one hand add Ube Halaya/Ube Jam filling and pinch the sides closed and place on a wax paper seam side down in a steamer tray. Seam side up if you created a fancy seam.
Roll top of bun on Latik for coating.