Add 150g of bread flour to your bowl.

Heat a bit over 150g of whole milk and when it comes to a boil weigh 150g and quickly add it to the flour.

With a wooden spoon or with a stand mixer mix the flour and milk until it forms a sticky dough. Wrap it in plastic and keep it at room temperature until you're ready to start the dough.

Mix the lukewarm milk, the whipping cream, the yeast, and the egg yolks, and let the mixture sit for 10 minutes.

Add the sugar to the egg mixture and give it a whisk.

In the bowl where you have your yudane add the egg mixture and break up the yudane a little bit.

Add flour and salt to the bowl where you have the yudane and pour the wet ingredients. Mix everything until you don't have dry flour particles. Cover and let it sit for 20 minutes.

After 20 minutes start kneading, if the dough feels too stiff and you didn't add all the milk, add a bit more. Once the dough starts coming together add the softened butter and continue kneading to incorporate it.

Knead until the dough becomes smooth and elastic. It shouldn't stick to your fingers and it should feel nice to the touch.

Place the dough in a lightly oiled container, cover it and let it ferment at room temperature for 2h or until it almost doubles in size

Deflate de dough gently and let it ferment again for 1 hour or until it almost doubles the size

After 1h or when the dough is ready deflate it gently and let it rest, covered, for 10 minutes.

Divide the dough into as many buns as you'd like, shape the pieces into small balls and let them rest covered for 10 minutes. This recipe can make 25 small buns, 12 medium buns, or 6 large buns.

Take one dough ball and flatten it with your hands or a rolling pin into an oval of half centimeter thick (1/4 in). For small-size buns, the oval will be 15x7cm. Starting from the short side roll the dough into a log and seal the edges.

Put the buns on baking trays separate enough they won't touch each other while they bake, cover them loosely with plastic wrap and let them ferment until they get puffy and have grown in size.

Before the buns finish proofing preheat your oven at 360F/180C (lower to 340F if you're making larger buns).

When the buns are ready, brush them with a mix of milk and the leftover egg white, make three cuts across the surface of each bun and bake them at 360F/180C for 25-35 minutes or until they have a nice golden brown color.

Let the buns cool down to room temperature. You can keep them in a seal-tight container or ziplock bag at room temperature. You can also freeze them and defrost them in the toaster.