In a large bowl of an electric mixer, combine the water and milk powder. Stir so that the milk dissolves. Add the yeast and the sugar, then let sit for about 5 minutes, until yeast bubbles up and mixture looks frothy.
Add in the salt, butter, egg and 1 cup of the flour. Mix on medium speed for 2 minutes. Add in remaining flour and mix another 2 minutes on medium speed. Set timer and mix on low speed for 5 minutes.
Scrape dough off sides of the bowl. (Dough will be soft & sticky.) Spray top of dough with non-stick cooking spray. Cover bowl with plastic wrap and let sit in a warm place for 1 hour, or until doubled in size.
Preheat oven to 350 degrees F. Spray a 10" round Springform pan (or use a 9x13 glass dish) with non-stick spray and set aside.
Punch down dough. Spray a clean countertop with non-stick spray and transfer dough to counter. Dough will be very soft. Try not to add additional flour as it will result in a tougher roll. (This is why I use non-stick spray instead of flouring the countertop!) Spray the rolling pin with non-stick spray as well and roll dough out into a 1/2" thick rectangle.
Spread filling mixture over the top of the rectangle. Roll up dough along the long side, pinching the end to the roll to seal it.
Use a sharp knife or plain dental floss to cut 1"- 1 1/2" segments. Transfer rolls to prepared pan. Rolls will be soft & delicate, so work quickly.
Cover rolls with a clean dishcloth and set on top of the warming oven for 30 minutes.
Bake rolls for 25-28 minutes, until golden brown on top. Remove from oven and let cool 5 minutes. Brush with glaze and serve warm.