Mix the cold milk with salt and the sugar. Mix using a fork until the sugar is dissolved. Melt the butter on low in a small saucepan. Turn the heat off and add the milk mixture. Add the active dry yeast. Mix and let the mixture sit for five minutes or until bubbles are formed.
Put one and a half cup of all flour purpose flour in the mixing bowl. Add the egg and let the hook attachment turn ten times. Add the yeast mixture and mix for five minutes. Add in one fourth cup of flour and continue mixing for five more minutes.
If you want to use the dough for later, wrap the dough in a plastic wrap and freeze it at this stage. After freezing, thaw the dough to a room temperature then proceed to the next step. The only disadvantage of freezing the dough is that it does not rise as much. But proceed to the next step right away if you are making it right away.
When ready, transfer the dough in a floured surface and flatten it using a rolling pin. The thickness can be one-one-fourth inch or half inch.Fill with Ube Jam. Leave one inch space on one end unfilled. Please see notes for the Ube jam recipe link. This is wet dough so coat your hand with flour for easy handling. When ready, form the dough into a ball and put it back in the mixing bowl. Cover and let the dough double in size for one hour.
After an hour, release the air of the dough by punching or pushing it down and removing it from the bowl and form it to a ball. Put it back in the mixing bowl and let the dough sit covered for another thirty minutes. Line eight inch round pan and spray it with non stick oil.
Sprinkle your working surface with and coat the rolling pin with flour. Use a rolling pin to flatten the dough to one fourth or half an inch thick. Fill with the Ube jam, leaving an inch unfilled. Please see the notes for Ube jam recipe.
Roll the dough and seal. Cut the dough using a kitchen twine and arrange in the prepared pan. Let the dough rise for another thirty minutes.