In a small bowl, mix ¾ cup of sugar with orange zest; set aside.
In a large bowl, dissolve the yeast in warm water. Beat in ¼ cup sugar, salt, eggs, sour cream and 6 tablespoons melted butter. Gradually add 2 cups of flour; beating until the dough forms.
Transfer to a floured surface. Into dough, knead enough remaining flour in small amounts to make it smooth and elastic with small blisters on the surface. Place the dough in a large greased bowl. Cover loosely with a clean dishtowel and let it rise in a warm place (80 to 85°) until it has doubled in size, about 2 hours.
Punch the dough down and turn out onto a floured surface. Knead about 15 times. Divide into 2 equal parts. Roll each part into a 12-inch circle. Brush the circles with the remaining butter. Sprinkle with the orange-sugar mixture.
Cut each circle into 12 pie-shape wedges. Starting at the wide end, roll up the wedges (croissant-like). Place them point-side-down in two greased 9x13-inch pans (or use a large, rimmed baking sheet for all 24 rolls). Cover and let rise in warm place until almost double in size, about 1 hour.
Preheat the oven to 350° F.
Bake, uncovered, 15 to 20 minutes- or until golden brown.
GLAZE
In a medium saucepan, mix all glaze ingredients. Boil 3 minutes, stirring constantly.
Spoon the glaze over the buns while they are still warm.
Notes
Don't have a warm place for rising? Turn the light on in your oven and use your (closed) oven for rising. You can turn it on briefly (30 seconds) to provide a blast of warm air and then be sure to turn it off!