In a small bowl, whisk together the 1/4 cup granulated sugar and tbsp of cinnamon for your cinnamon sugar topping and set it aside. In a large bowl, whisk together the flour, sugar, salt and yeast. Set it aside. In a separate, microwave safe bowl, combine the milk, water and butter and heat it in 20 second increments until the butter is melted and the mixture is warm to the touch (about 110F). Pour it into the dry ingredients along with the egg and stir it all together until a soft dough forms.
Turn out the dough onto a lightly floured surface and use floured hands to knead the dough for 3 minutes. Then, place the dough into a lightly greased bowl, cover loosely and let it rest for 10 minutes. After 10 minutes, turn the dough back out onto your lightly floured surface and use a rolling pin to roll it out into a large rectangle (roughly 14x8 inches). Spread the softened butter all over the dough rectangle, then sprinkle the cinnamon sugar mixture evenly over the top.
Roll the dough up tightly, length-wise. Then use a sharp, serrated knife to gently cut into 10-13 even sized rolls. Place the sliced rolls into a greased 9" pie dish. Loosely cover the rolls and let them rise for 60-90 minutes in a warm, draft-free place until they are puffy and doubled in size. Pictured below before and after the rise.
Once they have risen, preheat the oven to 375F. Bake the cinnamon rolls for 25-28 minutes, or until lightly golden brown. Check about halfway through bake time and if you notice they are browning on top too quickly, then lightly cover them with foil so that the centers can finish cooking. Once they're done baking, let them cool slightly while you make the frosting.
For the frosting, in a medium bowl, use a whisk or hand mixer to whisk together the butter and cream cheese until combined and fluffy. Then add the vanilla, salt and confectioners sugar and mix until combined. Add the milk 1 tbsp at a time until the frosting is your desired consistency. Spread the frosting over the top of the warm cinnamon rolls and serve them up.
You can also make this dough the night before if you're having them as part of your breakfast/brunch. Just go through all the steps until you slice the rolls. Arrange them in the greased pie plate and then cover with plastic wrap and let them rest in the fridge overnight. The next morning, remove them from the fridge and let them do their rise in a warm place, then bake.
