Sprinkle yeast over warm water. Add one teaspoon sugar and stir to combine. Let sit for 5 minutes to activate yeast. Mixture will bubble and expand.
In the bowl of a stand mixer fitted with a dough hook attachment, combine dissolved yeast mixture, remaining sugar, milk and eggs. Add3 cups flour and salt. Mix on low speed until dough starts to form.
Add the butter one tablespoon at a time to the stand mixer. Add 1 cup of the remaining flour mixture and continue to mix for one minute.
Add in the remaining flour a little bit at a time, until the dough pulls away from the sides of the bowl. Knead on med-low until the dough is soft, smooth and springs back to touch, about 3 minutes.
Transfer dough to a lightly greased bowl. Cover with plastic wrap and let rise at room temperature for about an hour, or until almost doubled in size.
Punch down dough. Turn out the dough into a lightly floured surface. Roll dough to a 16x12-inch rectangle.