Make the dough: Whisk the milk, eggs, yeast and sugar in a large bowl.
170 grams whole milk, 2 eggs, 50 grams cane sugar
Stir in the dry ingredients and sourdough discard using a sturdy wooden spoon or spatula. Switch to your hands and bring the mixture together until a cohesive dough forms.
440 grams all-purpose flour, 8 grams salt, 113 grams sourdough discard, 7 grams instant yeast
Incorporate the butter into the dough gradually, one tablespoon at a time, allowing the dough to absorb each addition. As the butter is absorbed, the dough will progressively feel less greasy.
56 grams unsalted butter
Cover the bowl with plastic wrap and let the dough rest for 15 minutes.
Knead the dough: Turn the dough out on a lightly floured work surface. Knead the dough by folding it in half using the heel of your palm. Then apply light pressure to the dough and stretch it away. Rotate the dough a quarter turn and repeat for 5 to 10 minutes or until the dough looks smooth and elastic.
First rise: Round the dough into a tight ball and place it into a clean, lightly oiled bowl. Cover the bowl with plastic wrap and let the dough rise in a warm place until bubbly and doubled in volume, about 45 minutes to 1 hour.
Prepare the filling: In a small bowl, whisk together the brown sugar and cinnamon. Set aside.
150 grams brown sugar, 10 grams ground cinnamon
Shape the rolls: Turn the dough out on a lightly floured work surface. Using a rolling pin, flatten the dough out into a large rectangle, about 10-by-18 inches.
Spread an even layer of softened butter on the dough. Sprinkle the cinnamon sugar over the dough.
42 grams unsalted butter
Working with the longer side, roll the dough into a tight cylinder. Cut the dough into 9 portions, each portion should be about 2 inches.
Arrange the dough in a 10-inch cake pan lined with parchment paper (optional). Cover the pan with plastic wrap.
Second rise: Let the dough rise untouched until puffy and the rolls touch and fill the pan, about 30 to 45 minutes.
Prep: Preheat the oven to 350 F with a rack in the middle position.
Bake: Brush the rolls with heavy cream and bake the rolls for 30 to 40 minutes or until they are golden brown and the center of the rolls registers at 190 F when probed with an instant-read thermometer.
Make the glaze: Using a hand mixer or stand mixer with a paddle attachment, beat the cream cheese and powdered sugar until no lumps remain. Stir in the milk and butter until the frosting looks smooth.
14 grams heavy cream, 60 grams powdered sugar, 56 grams cream cheese, 28 grams milk, 14 grams unsalted butter
Serve: Spread the frosting over the warm rolls and enjoy. These rolls are best eaten the same day they are baked.
Storage: Store leftover cinnamon rolls in an airtight container in the refrigerator for up to 3 days.