Prepare the yeast: If using fresh baker’s yeast, crumble it into lukewarm milk (be careful, the milk shouldn’t be too hot) with a pinch of sugar, and let it sit for 10 minutes until it foams. For dry yeast, mix it directly into the flour.
Mix the dry ingredients: In a large bowl or the bowl of your stand mixer, combine the flour, sugar, and salt.
Add the eggs and milk: Make a well in the center of the dry ingredients and add the beaten eggs and the milk with the yeast. Mix until a smooth dough forms.
Add the butter: Gradually incorporate the softened butter, kneading the dough for about 10 minutes, until it becomes smooth, elastic, and pulls away from the sides of the bowl. The dough should be soft and slightly sticky. Let it rest: Cover the bowl with a clean cloth and let the dough rise in a warm place for 1 hour, or until it has doubled in volume.