In the first step, prepare 2 mixing bowls. In the first mixing bowl, mix condensed milk, water, and yeast together and let it rest for 2-3 minutes.

Then, mix the second bowl including flour, egg, and salt together.

Add the milk and yeast mixture to the flour & egg mixture, and knead until the dough comes together in one piece. The texture might not be smooth at this step. Next, add butter in and mix well until you achieve a smooth, round dough. Let the dough rest for at least 15 minutes more.

After resting, continue kneading the dough until it passes the windowpane test. (FYI: The windowpane test is a technique to check the development of gluten in the dough. To perform the test, take a small piece of dough and gently stretch it out with your fingers of both hands to make it as thin as possible. The dough should stretch without tearing, becoming thin enough to let light pass through like a windowpane. See the example image below).

Now, let the dough rise until it doubles in size. This process usually takes about 2 hours, but it can vary depending on the temperature and moisture of the room. You can use a cylindrical cup to estimate the rise of your dough: add a small amount of the dough, mark its height, and wait until it doubles in height.

Divide the dough into 4 equal parts and shape each into small round balls. Let the dough rise again until it doubles in size.

Preheat the oven to 175°C (350°F), then bake the bread for 15 minutes. Check the oven regularly to ensure that the breads are neither underbaked nor overbaked. Allow them to cool down before enjoying.