In a medium sauce pan, pour water, 2 1/2 tablespoons sugar, salt, ube extract, and vegetable oil. Bring to a boil and then remove from heat. Stir in flour until mixture forms a dough ball
Heat oil for deep frying to 375°F
Transfer dough into a piping bag fitted with a medium star tip. Pipe 4-6 inches of dough straight into the hot oil. Do not overcrowd the fryer. Its a little difficult to see the deep purple dough turn brown so use your best judgment. Remove from oil and let churros dry on paper towels.
In bowl or on a plate, combine 1/2 cup sugar and cinnamon. Roll the churros in this mixture
If you want to make the optional dip, add ube halaya into a small bowl and slowly add milk as you mix to get the consistency you want.