Make the ube dough

• Warm the milk and dissolve the yeast with a spoonful of the sugar.
• In a bowl, combine the flour, remaining sugar and salt, then add the egg, softened butter and ube extract.
• Knead into a smooth, elastic dough.

Let the dough rise

• Cover the bowl and leave the dough in a warm spot until doubled in size.

Cook the blueberry filling

• Simmer the blueberries with the sugar, cornstarch and lemon juice, stirring, until thick and jammy.
• Mash lightly and let cool completely.

Roll and fill

• Roll the dough into a large rectangle on a floured surface.
• Brush with melted butter and spread the blueberry filling evenly.
• Roll up tightly and cut into even slices.

Second rise

• Arrange the rolls in a buttered baking dish and let them puff up.

Bake the rolls

• Bake at 180 °C until golden and cooked through.

Make the ube cream cheese frosting

• Beat the cream cheese and butter until smooth.
• Add the powdered sugar, milk and ube extract and beat until creamy.

Frost and serve

• Spread the frosting over the warm rolls and serve.