In the bowl of a stand mixer, combine the warm milk, half of the sugar, and yeast. Let the mixture sit for about 5–10 minutes, until foamy. If using instant yeast, you can skip the activation step and mix it directly with the dry ingredients.
Add the plain yogurt and half of the flour. Using the dough hook attachment, knead until the flour is absorbed.
Add the remaining flour, remaining sugar and salt. Knead for 5 - 10 minutes until the dough begins to come together.
Add the softened butter and continue kneading for another 5–7 minutes, until the dough is smooth, soft, and slightly tacky. It should be stretchy but not overly sticky.
Transfer the dough to a lightly greased bowl. Cover and let rise in a warm place for about 1 hour, or until doubled in size.