Whisk warm water, milk, and yeast in a mixer for 5-10 minutes until frothy. Add 2T sugar, butter, first 130g flour, and salt on low speed. Scrape bowl as dough forms.
Knead dough on medium speed, adding remaining flour gradually until smooth and elastic (5-7 minutes). Let rise in a warm, damp environment for 1 hour, or until doubled.
In a small bowl, mix 2T sugar with 2 tsp cinnamon. Pat dough into a square, spread cinnamon-sugar mixture across center with a 1″ margin. Fold sides over, roll tightly, and place in a greased loaf pan.
Brush egg white over dough for golden shine. Let rise again for 30 minutes. Bake at 375°F (190°C) for 35-45 minutes. Cool before slicing.