In a mixing bowl, combine 3 cups of cake flour, 2 teaspoons of instant yeast, and 1 teaspoon of salt. Gradually add 1 cup of room-temperature whole milk, ⅔ cup of sweetened condensed milk, and 1 large egg. Mix on low until a cohesive dough forms, about 2-3 minutes. Once combined, add ¼ cup of softened unsalted butter and continue mixing until the dough is smooth and elastic, approximately 5 minutes.

Transfer the dough onto a lightly floured surface and knead it gently for about 1-2 minutes until it forms a smooth ball.

Place the kneaded dough into a greased bowl, cover it, and let it rise in a warm area until doubled in size, approximately 1.5 to 2 hours.

Once risen, deflate the dough and roll it out into a rectangle about 12x18 inches. Tightly roll the dough into a cylinder shape and cut it into equal pieces, about 1.5 inches thick.

Arrange the dough pieces in a greased baking pan, cover loosely with a kitchen towel, and let it rise again until nearly doubled, about 1 to 1.5 hours.

Preheat your oven to 350°F (175°C). Brush the tops with the egg wash and bake for 35-40 minutes, turning halfway through.

After baking, brush the top with the condensed milk glaze and allow it to cool in the pan for 10-15 minutes before transferring to a wire rack.