Dissolve the yeast in the warm milk. Add a tsp of sugar from the sugar needed for the dough to help activate the yeast. Let it sit for 5 to 10 minutes until it has foamed up nicely.
In your mixers' bowl mix the eggs, sugar, butter, salt. Once all nicely combined add 3.5 cups of the flour, mix till just incorporated and then pour the milk/yeast mixture over the flour mixture. Allow this to come together, kneading with a dough hook until well incorporated. Add remaining flour in ½ cup increments. You don't want a dry dough. 4-4.5 cups could be enough!! You want a smooth, clean dough, not too sticky.
7minutes in a Kitchenaid or Breville stand mixer It'll come off the sides of your mixing bowl. By hand possibly 15min - Knead until smooth and elastic.
Place the dough into an oiled bowl, cover and let rise in a warm place about 1 hour or until the dough has doubled in size.
Combine the brown sugar and cinnamon in a bowl.