In a large bowl, beat together the milk, sugar, butter, egg, salt and ube essence. Add the rehydrated ube powder and beat until combined. Set aside.
In another large bowl, whisk together the flour and yeast. Add the wet ingredients (milk mixture) and mix until smooth.
Transfer the dough to a lightly floured surface. Knead dough, adding more flour as necessary, until dough is smooth.
Place the dough in a lightly greased bowl, cover with plastic wrap and let sit for 1 hour.
Transfer the dough to a lightly floured board. Divide the dough into 20 pieces. Flatten each piece and then spread ½ teaspoon of the sweet purple yam spread on top. Place a piece of cubed cheese on top of the yam spread. Seal and shape into a ball, roll in breadcrumbs and then place in a baking pan lined with parchment paper. Repeat with the rest of the dough pieces.
Cover with a cloth and let rise until double in size. Rising time may vary depending on the humidity.
Bake in 225 degree F preheated oven for 20 minutes and then increase the oven temperature to 325 degree F while keeping the pan de sal in the oven. Bake for another 10 to 15 minutes until golden brown. Serve warm.