In a large mixing bowl, combine flour, sugar, and yeast, creating a well in the center. Gradually add warm milk and melted butter, mixing until a soft dough forms.

Transfer the dough to a floured surface and knead for about 10 minutes until it becomes smooth and elastic.

Place the kneaded dough in a greased bowl, cover with a kitchen towel, and let it rise in a warm area for approximately 1 hour.

In a separate saucepan, whisk together eggs, sugar, and milk for your custard filling. Cook over low heat, stirring until thickened, about 10-15 minutes.

Once your dough has risen, gently punch it down, roll it out into a rectangle, and spread the custard filling evenly over it.

Grease a baking dish, place the rolled dough seam-side down, cover again, and let it rise for an additional 30-45 minutes.

Preheat the oven to 350°F (175°C). Bake the custard-filled sweet bread for 25-30 minutes until golden-brown.

Allow to cool slightly in the pan before transferring to a wire rack. Dust with powdered sugar before serving.