Add 3/4 cup of milk and 1/4 cup of all-purpose flour to a saucepan. Whisk until thickened, to a paste consistency and there is no longer any flour visible. This paste is known as Tangzhong.
In a large bowl combine 5 cups of flour, yeast, salt, and sugar. Warm-up 1 1/2 cups of milk in the microwave until warm. Don't allow it to get too hot as it will kill the yeast.
Add warm milk to the flour mixture, along with an egg, and Tangzhong. Mix using a stand mixer, or hand mixer with the dough hook attachment, or knead by hand. Beat at low speed, gradually increasing speed being sure to scrape down the sides of the bowl. Beat until dough is smooth, soft, and elastic. Approximately 15-20 minutes.
Test if the dough is ready by taking a small amount, rolling it into a ball, and stretching it between two fingers. If the dough does not break and you can see through it, it is ready and the gluten has formed. If not continue beating.
Add in butter and beat at medium speed until butter is fully incorporated. Dough should pull away from sides of bowl and form a ball when ready.
Spray a medium bowl with non-stick spray. Transfer dough into a bowl and cover with plastic wrap. Place in a warm place to allow the dough to proof and double in size, for approximately 1 hour.
While dough proofs, create filling by adding butter to a saucepan. Once melted add in light brown sugar, orange zest, ground cinnamon, ground cardamom, and a pinch of salt. Mix until incorporated, take off the heat and allow to cool.
Once the dough has doubled in size. Punch down dough and roll out onto a floured surface. Roll out to about 18x12 inches. Spread filling onto dough making sure to reach all edges.
Starting at the long edge, begin to roll the dough into a log. Making sure to end with the seam side facing down. Using a sharp serrated knife cut off the ends, then continue to cut the dough into 12 even rolls.
Place rolls in a greased 9X13 baking dish, cover with a damp dish towel or plastic wrap and let sit in a warm place to proof again for approximately 1 hr.
Once rolls have doubled in size. Pre heat oven to 350℉. Bake for 30 minutes until rolls have puffed up and are golden brown.
While baking, make the frosting. Beat butter and cream cheese together until smooth. Add in powdered sugar, vanilla, orange juice, and salt. Beat until smooth.
Let the orange cinnamon rolls cool in a pan 5-10 minutes. Once cooled spread frosting all over.