Combine milk and water in a heatproof dish and warm in the microwave until 105-115F (40-46C) (stir before checking temperature).
Pour the milk mixture into a large bowl (you could also use a stand mixer for this recipe), add the yeast and sprinkle in a generous pinch (about 1 teaspoon) of granulated sugar. Stir and allow to sit for about 5-10 minutes until yeast is foamy (if yeast does not foam see my FAQ section, you will need to start over).
Once yeast is foamy, add ⅓ cup granulated sugar, melted butter, eggs, salt, 2 cups (250g) of flour, and orange zest. Stir well until ingredients are well-combined.
Gradually add additional flour (if using a stand mixer use the dough hook attachment and low-speed) until the dough clings to itself and pulls away from the sides of the bowl. Add flour until the dough is slightly tacky to the touch. If making by hand, transfer to a clean, lightly floured surface and knead for 5-10 minutes until the dough is smooth and elastic (if using stand mixer, mix on low/medium speed for 3-5 minutes). Add more flour as needed.
Transfer to a large lightly oiled bowl and turn the dough to lightly coat the entire surface with oil. Cover and allow it to rise in a warm, draft-free place until doubled in size (about 1-2 hours).
Meanwhile, prepare your filling by whisking together ⅓ cup granulated sugar and ground cinnamon. If your butter for the filling is not easily spreadable, pop it in the microwave for a few seconds until slightly melty. Use 2 tablespoons of butter to generously grease the sides and bottom of a 9×13 baking dish and set aside.
Once dough has risen, punch down and transfer to a clean lightly floured surface. Roll to a 10×20” (25x50cm) rectangle.
Spread 4 tablespoons of butter (reserve 2 tablespoons for greasing pan) evenly across the surface of the dough, leaving a ¼” (½ cm) perimeter of the dough unbuttered. Sprinkle evenly with cinnamon/sugar.
Starting with one 20” (50cm) end, roll dough tightly into a log. Cut into 12 even pieces and space them evenly in greased pan. Cover with a clean towel and allow to rise until the gaps between the rolls have been mostly filled, about 30 minutes. Meanwhile, preheat oven to 350F (190C).
Once rolls have risen and oven is preheated, remove towel and bake in 350F (175C) oven for 25 minutes (if using a glass baking dish you may need longer) or until cooked through (I use a knife to check if the cinnamon rolls are cooked through or still gooey inside).
While rolls are cooling, prepare your glaze by whisking together sugar, butter,and orange juice. Drizzle or spread over rolls while still warm. Enjoy!