Warm the milk to just room temperature.
Add egg and yeast to milk and mix together and set aside.
In a large bowl or stand mixer, combine flour, cardamom. salt, and sugar.
Slowly pour in milk, egg, yeast mixture to the flour mixture.
Now add in your softened butter.
Using a paddle or spatula, mix together until well combined.
Knead the dough for 10-15 minutes either using a dough hook or by hand.
Cover the dough with plastic wrap or towel and let rise in a warm spot to rise for 40-45 minutes. (The dough should double in size during this time)
Form dough into a rectangle shape and continue rolling out into a large rectangle about 1/8 inch thick. About 20 by 12 inches.
Mix together the filling of butter, sugar and cinnamon and spread on top of dough.
Roll the dough on the long side and cut slices that are about 3/4 inch thick. You'll get about 25 slices.
Place them on a parchment lined baking sheet and cover with towel and let rise for 1 hour until doubled in size.
Mix together the egg and water and brush mixture over cinnamon buns. Then sprinkle pearl sugar over top.
Bake in oven at 425℉ for 5 minutes, then lower temperature to 375℉ and bake an additional 10 minutes.
Allow to cool on rack for 5-10 minutes before serving. Enjoy!