Add warm milk to mixer.
Sprinkle yeast on top (DO NOT MIX). Wait at least 5 minutes, until yeast foams.
After yeast foams, add egg, egg yolk, butter and sugar. Mix ingredients until combined.
Sift in flour and salt, a little bit at a time. Use a wooden spoon to mix, until a dough forms.
Place dough hook on mixer, and mix for 8 minutes, ensuring that the dough is a nice ball.
While dough is mixing, oil a bowl (Butter is perfect). Transfer dough to bowl, and lightly oil the top of the dough.
Cover bowl with a towel, and place in a warm area for 2 hours (Place on top of pre-heated oven).
Once dough has risen, transfer dough to a well floured surface, and roll it out in a rectangle. Try to stretch the dough out as far as possible, without ripping it.
Mix together cinnamon and brown sugar.
Spread butter over dough, leaving space around the edges.
Sprinkle the cinnamon sugar mixture over the middle of the dough. Then, lightly pressing down, rub it into the butter.
Tightly roll the dough (rolling it so that it is long, not thick).
Cut each section into 1 - 1 1/2 inch (Ideally, you would get 9 large cinnamon rolls).
Line a baking dish with parchment paper, and place rolls on dish.
Place plastic wrap over baking dish, and cover with a towel. Let rest in a warm area for at least 30 minutes to 1 hour, in order for rolls to rise again.
Remove plastic wrap and towel, after second rise. Bake for 15-18 minutes at 350 degrees (Rolls should be lightly browned).