Step 1 Stir together one-half cup warm milk, yeast and a pinch of sugar in a small bowl until the yeast is dissolved. Let stand until foamy, about 5 minutes. (If mixture doesn't foam, discard and start with new yeast.)
Step 2 Put the flour, remaining sugar and salt in a mixer bowl and mix with a dough hook at low speed until combined.
Step 3Whisk together the remaining 1 cup milk and the eggs in a small bowl, then add to dry ingredients along with the yeast mixture and mix at medium speed until a very soft dough forms, about 2 minutes. Add the butter and continue beating until the dough is smooth and elastic, about 4 minutes (dough will be very sticky).
Step 4Rinse a large bowl with hot water, then put the dough in the wet bowl and cover tightly with plastic wrap. Let the dough rise in a warm draft-free place until doubled in bulk, about 1 1/4 hours.