1Dissolve the yeast in 1/2 cup warm water (roughly 105-115F)for about 1 minute. Stir the yeast and water around, then add orange zest, orange juice, sugar, salt, egg, butter, and 1 1/2 cups of flour. Using a mixer, beat everything together on low, scraping down the sides as needed. With a wooden spoon, stir in enough of the remaining flour to make a dough easy to handle - about 1 1/2 - 2 more cups. You are looking for a dough that is not sticky and will spring back when poked with a finger.
2Use the mixer to knead the dough for about 5 mins. Remove the dough from the bowl and lightly oil the bowl. Form the dough into a ball and return it to the bowl. Cover the dough and let sit in a warm place until doubled in size, about 1.5 hours.
3Line the bottom of a 9x13 inch baking dish with parchment paper or a silicone mat,leaving room on the sides. Turn the dough out onto a lightly floured work surface and, using a rolling pin, roll into a 15x9 inch rectangle, making sure the dough is smooth and evenly thick, even at the corners.
4To make the filling -in a small bowl, mix together the sugar and cinnamon. Spread the dough rectangle with softened butter and sprinkle generously with all of the cinnamon-sugar mixture. Tightly roll up the dough into a log (rolling from the long side), pinching the seam closed and cut it into 16 even rolls (1 inch in width each) with a very sharp knife. Arrange them in the prepared baking pan, cut sides up. Cover the rolls and let them rise in a warm place for about 30 minutes - 1 hour.
5Preheat the oven to 375F degrees. Cover the rolls with aluminum foil and bake for about 25-30 minutes, until they are lightly golden in color. Transfer the pan to a rack to cool for about 15 minutes.
6In a small bowl, mix together all of the glaze ingredients and drizzle over rolls before serving.