Put your warm water, sugar, powdered milk, salt, 3/4 of the stick of butter, sourdough discard and 2-3 cups of flour in your stand mixer.
Mix with the paddle until the mixture come together. I use my KitchenAid Add your eggs, 1 at a time.
Mix well, then add 1 cup of flour.
Once that flour has been mixed in, add your yeast slowly.
Once the yeast is mixed in, switch to a dough hook anf add the rest of your flour slowly. This dough will be very sticky, but that is what you want!
I usually end up using 6 cups of flour. Yours may be different. But let me make something clear. Make sure you are not packing your flour down before using. I like to fluff mine up, or you can use a whisk to lighten it. Do not flatten and level off the measuring cup, this will give you an overage of flour. Keep the flour light and fluffy.
Once you have the rest of the flour mixed in, you want to let the dough knead for 3 or 4 minutes.
Next, you can transfer the dough into a large oiled bowl. Cover with plastic wrap and let it sit and rise until it doubles in size. This could take 30 minutes to an hour. This is the first rise.
Once it has risen to double its size, punch it down and let it rise one more time.
Once it has risen a second time, you are ready to roll out your dough to make your orange rolls.
Making the orange rolls is pretty easy. Roll the dough out into a large rectangle on a lightly floured surface. You want your dough to be about 1/4 to 1/2 inch thick. I use my Roulpat to roll my doughs and bread out. It is an amazing kitchen essential. In a medium bowl, add the butter, sugar and orange zest. Use a fork to mix it all together until everything is incorporated and forms kind of a paste. Spread the filling on the entire surface of the dough, try to spread it evenly without tearing the dough. Do this gently.
Starting at the long end of the dough, begin rolling it up. When you get to the end, brush a small amount of butter or water on the end of the dough. Take the end and stretch it over the roll all the way down the dough roll.
Use a piece of thread or unflavored dental floss to cut the cinnamon roll. Take the thread and slide it under the roll, bring it up and across, twisting the thread, cutting the dough all the way through. This gives you a clean cut and does not smash the dough.
Place your orange rolls on a greased sheet pan. I use the 12 by 18 size. This will hold 24 cinnamon rolls. 4 across, 6 down. If you half this recipe you can use a 9 by 13 pan to make 12 rolls.
Once they are all cut and in place, cover the pan with plastic wrap while the oven preheats to 350 degrees F. Let the dough rise for about 20-30 minutes, or until they are almost doubled in size.
Bake them in the oven for 20-30 minutes. Check them at 20 minutes. If you tap them and they feel squishy, they need more time.
You want them to be light golden-brown on the top, and when you tap them they are soft but somewhat firm.
Take them out of the oven and let them cool for a bit while you make the frosting.