Start by slicing the butter into 1/4" pieces and allow them to soften at room temperature. Using a stand mixer fitted with a dough hook, combine eggs, milk, sugar, and sourdough starter in the mixing bowl. Whisk until the mixture is smooth. Add the flour and salt, mixing on low speed for 3 minutes to incorporate. Let the dough rest for 10 minutes. After resting, increase the mixer speed to medium and mix for 5-6 minutes until the dough forms and is free of lumps. The dough should pull slightly from the bowl sides but still stick to the bottom. If the dough seems too wet, gradually add flour, one tablespoon at a time. Lower the mixer speed and add the butter pieces one at a time, waiting for each to blend before adding the next. Continue mixing for 8-10 minutes until the dough is shiny and smooth.

Place the dough in a bulk container and ferment it for 2 hours at 75ºF (23°C), performing 3 to 4 sets of stretch and folds every 30 minutes.

Cover the container and refrigerate the dough for at least 2 hours to chill thoroughly.

Prepare the filling by mixing the ingredients in a bowl and setting them aside. Flour your work surface lightly, then roll the chilled dough into an 11×21" rectangle with the long side facing you. Evenly spread the filling over the dough, then roll it tightly away from you into a log. Slice the log into 1 3/4" pieces and arrange them in a baking pan with space between each roll.

Cover the baking pan and let the rolls proof in a warm spot, around 77°F (25°C), for 2 to 3 hours. The rolls will soften and rise. They are ready to bake when they are soft and light to the touch; allow extra time if needed.

Preheat the oven to 400°F (200°C). Once the oven is ready, bake the rolls for 20-25 minutes. After baking, let the rolls cool slightly before spreading the cream cheese glaze over them.