In a large mixing bowl, combine 4 cups of all-purpose flour, 1/4 cup of sugar, 2 teaspoons of yeast, and 1 teaspoon of salt. Warm 1 cup of milk to about 110°F, then add 1/4 cup of melted butter. Pour the warm milk mixture into the dry ingredients and stir until a dough begins to form.

Transfer the dough onto a floured surface and knead it for about 5-7 minutes, until it becomes smooth and elastic.

Place the kneaded dough in a greased bowl, cover with a towel or plastic wrap, and let it rise in a warm place for about 1 hour or until doubled in size.

Prepare your custard filling according to your recipe or package instructions and let it cool completely.

After the dough has risen, punch it down gently, roll it out into a rectangle about 1/2 inch thick, spoon the cooled custard over the dough, roll it tightly into a log, and pinch the edges to seal.

Grease a baking dish and place the shaped bread inside, seam side down. Cover and let it rise for an additional 30-45 minutes.

Preheat your oven to 350°F (175°C) and bake the bread for about 25-30 minutes until golden brown and hollow sounding.

Let the bread cool in the pan for 10 minutes, then transfer to a wire rack. Dust with powdered sugar before serving.