In a large mixing bowl, combine 1 cup of warm water (about 37-40°C or 98-104°F), 4 teaspoons of sugar, and 1 tablespoon of yeast. Stir gently to combine.

Let the mixture sit for 5-10 minutes, or until the yeast becomes foamy. This step is essential for ensuring the yeast is active and will help the dough rise properly.

Once the yeast mixture is foamy, add 1/3 cup of vegetable oil and 1 cup of warm milk (around the same temperature as the water). Stir to combine the liquids thoroughly.

Add 1/2 teaspoon of salt to the wet mixture and begin adding the flour gradually. Start by adding 4 cups of flour (600 grams) to the bowl, stirring with a wooden spoon or spatula until a dough begins to form.

Continue adding flour, 1/2 cup at a time, until the dough is soft but not too sticky. You may not need the full 5 cups, so add the flour gradually to avoid overloading the dough.

Turn the dough onto a lightly floured surface and begin kneading it by hand. Knead for about 8-10 minutes, adding a little extra flour as necessary to prevent sticking. The dough should become smooth, elastic, and slightly tacky, but not sticky.

Shape the dough into a ball and place it into a lightly greased bowl. Cover the bowl with a clean kitchen towel or plastic wrap.

Let the dough rise in a warm, draft-free place for about 1-1.5 hours, or until it has doubled in size. This will depend on the temperature of your kitchen, but a good spot for rising is often a warm oven (turned off) or near a window with sunlight.

After the dough has risen, punch it down to release the air and transfer it back to your work surface.

Divide the dough into 8 equal portions. Roll each portion into a ball, then flatten each ball slightly with your hands or a rolling pin.

Place 1 part of the softened butter (about 12-13 grams) in the center of each flattened dough piece, then fold the edges up to cover the butter. Roll the dough back into a smooth ball, ensuring the butter is sealed inside.

Arrange the rolls, seam side down, in a greased baking dish or on a parchment-lined baking sheet, leaving a little space between each roll for expansion.

Cover the rolls with a kitchen towel and allow them to rise again for about 30-40 minutes, or until they have doubled in size.

Preheat your oven to 180°C (350°F) about 15 minutes before baking.

Once the rolls have finished their second rise, bake them in the preheated oven for 20-25 minutes, or until they are golden brown on top and cooked through.

Remove the rolls from the oven and brush them with a little melted butter for an extra soft and glossy finish.

Let the rolls cool for a few minutes in the baking dish before serving. These rolls are best enjoyed warm, with butter, jam, or as a side to your favorite meal.