In a small pot, whisk the water and all-purpose flour together. Cook over medium heat, whisking constantly, for 4-5 minutes until the mixture is thick and paste-like. Scrape it into a bowl and set it aside.

In a stand mixing bowl, mix the all-purpose flour, sugar, yeast, and salt until combined. Then add the milk, egg, vanilla, and tangzhong. Knead on low speed until it forms a rough dough ball.

Gradually mix in the softened butter, one tablespoon at a time, ensuring each addition is incorporated fully. Knead for 10-11 minutes or until the dough becomes smooth and elastic, sticking just to the bottom of the bowl.

Using buttered hands, shape the dough into a smooth round ball, ensuring the seams are at the bottom. Place the dough seam side down in a buttered bowl, cover with plastic wrap, and let it rise in a warm spot for approximately 1 hour or until it doubles in size.

Lightly grease an 8x3 spring form pan. See notes below for other pan sizes.

Combine the butter, brown sugar, and cinnamon until smooth.

Roll the dough out on a lightly floured surface into an 18x12 rectangle. Spread the brown sugar cinnamon filling to the edges.

Cut six 2-inch strips. Roll up the first strip, then continue rolling it with the second and third strips. You will have a large cinnamon roll now. Lift the next strip and wrap it around the roll, repeating with the remaining two strips. Transfer the giant roll to the greased springform pan. Cover the top with plastic wrap, and let it rise in a warm place until doubled in size and fills the pan, another 45-60 minutes. The middle of the roll will likely puff up out of the pan. You can gently press the center back down before baking. Preheat the oven to 325°F (162°C) during this time.

Bake for 50-60 minutes, covering with foil after 25-30 minutes (or when the top gets light golden brown). To test for doneness, insert an instant-read thermometer at an angle into the middle part of the roll. It should read 170 F/78 C when it’s done baking! Take it out of the oven and place it on a wire cooling rack. Unlock the clasp and remove the sides of the pan. Let it cool while you make the frosting.

Mix the cream cheese, butter, and powdered sugar in a stand mixing bowl until smooth. Then mix in the heavy cream, vanilla, and salt.

Spoon the glaze over the warm cinnamon roll cake so that it melts down into the cake for gooey centers. You may not care to use all of the icing, which is fine! Then cut into slices and enjoy!