In a microwavable mug, heat up the water for 20-25 seconds until lukewarm.
Add yeast and 2 tsp sugar and stir. Set a timer for 5 minutes. This is the time it takes for the yeast to grow. Watch so that it will not overflow. This is the yeast mixture.
In a glass measuring cup, microwave the the milk for 1 minutes until warm.
In a stand mixer, mix together the 2/3 cup sugar, salt, butter and 2 cups of the flour. Stir this with a wooden spoon.
Add the warm milk, yeast mixture and 1 egg. Mix well and rest 5 minutes.
Put on the dough hook attachment. While the mixer is on low, add 2-3 cups (up to 3 1/2 cups) of flour, 1 cup at a time. Mix the dough every time you add flour. Knead again for 5-6 minutes.
Grease a large bowl with butter. Scrape the dough and pour it unto the bowl. Turn the dough so that all is covered with butter.
Cover with tea towel. Let rise for about 1 hour. Grease 2 9×13 pan with butter.
Punch down the dough. Divide into 24 equal pieces and shape into balls. Divide the rolls into the 2 pans. There should be 1 cm space between rolls for it to rise.
Cover with tea towel. Let rise for about 45 minutes until doubled in size. Preheat oven to 375 degrees F.
Bake for 12-15 minutes until golden brown. Remove from oven and brush the melted butter.