Mix milk and warm water together in medium mixing bowl. Stir in sugar and yeast, set aside for 10 mins (should become bubbly, which means your yeast is active).
Combine flour and salt in large mixing bowl. Add yeast mixture and combine using a wooden spoon. Once dough has formed, turn out onto lightly floured surface.
Knead dough until smooth dough ball forms, incorporating as little flour as possible (just enough to keep it from sticking).
Pour small amount of oil into large bowl and roll dough in oil, to coat completely. Cover bowl tightly with plastic wrap and place in refrigerator overnight (if you are pressed for time you can also place dough in a warm area until it doubles in size, about 2 hours).
Preheat oven to 375 degrees. Blend sugar, brown sugar, and cinnamon in small bowl; set aside.
Remove risen dough from refrigerator and punch down dough. Place dough on lightly floured surface and cut in half.
Using a rolling pin, roll each half into a 9" x 18" rectangle and sprinkle with sugar mixture.
Beginning with the short side, roll each piece of dough like a jelly roll and place dough into loaf pans, crease side down (well-greased and floured pans make for easy unmolding).
Cover loaves with dishtowels and let dough rise until it doubles in size (about 1-2 hours).
Whisk egg in small bowl and brush egg over tops of loaves then bake 45-55 minutes. Remove from oven; let sit 10 minutes to cool before devouring.
Notes
Yeast is activated between 110-115 degrees. Going over 115 degrees could kill your yeast.