Soften the butter at room temperature.
In a large mixing bowl, whisk together the milk, condensed milk, egg, salt, and yeast.
Sift the all-purpose flour into the same bowl and mix with a spatula until combined.
Continue mixing and folding the dough until the ingredients are fully incorporated.
Add the softened butter to the dough and mix thoroughly until well combined.
Transfer the dough to a floured surface and knead it by hand for 15 to 20 minutes, until smooth.
If the dough becomes too sticky to knead, set aside one tablespoon of all-purpose flour and sprinkle it over the dough as needed.
Place the dough in a buttered bowl and cover it with a cloth or plastic wrap.
Let the dough proof in a warm area for 1 hour, or until it has doubled in size.
After the first proofing, transfer the dough to a floured surface and gently press to release the air.
Divide the dough into two equal portions.
Flatten and shape each portion into a 16 x 8-inch rectangle, then roll it up and pinch the seam to seal.
Place the seam side down and cut the dough into equal pieces with a knife, similar to making cinnamon rolls.
Line the cut dough pieces in a loaf pan and cover them lightly with plastic wrap.
Let the dough rise in a warm area for 45 minutes.
Repeat this step with the second loaf.
Once the loaves have doubled in size, brush them with an egg wash.
Preheat the oven to 180°C (356°F) and bake the loaves for 22 minutes, or until golden brown.
Meanwhile, prepare the glaze by combining the condensed milk with softened butter in a small bowl.
After baking, remove the bread from the loaf pan immediately.
Brush the bread with the condensed milk glaze and serve warm or at room temperature.
