To make Cinnabon-style cinnamon rolls without yeast, start by preheating your oven to 425°F (220°C). First, prepare the filling by mixing brown sugar, granulated sugar, cinnamon, and salt in a bowl until well combined.
Next, prepare the dough. In a large bowl, combine flour, sugar, baking powder, baking soda, and salt. In another bowl, whisk together buttermilk and 4 tablespoons of melted butter. Pour this mixture into the dry ingredients and stir until the dough just comes together.
Lightly knead the dough with your hands to form a ball. Divide it into two halves. On a floured surface, roll each half into a 12×8″ rectangle. Spread half of the filling mixture onto each rectangle, leaving a 1/4″ border. Roll the dough tightly like a sausage and pinch the seam shut. Cut each roll into 8 slices.
Place the rolls in a non-stick sprayed pan. Brush the tops with the remaining tablespoon of melted butter. Bake for about 15 minutes or until the tops are golden brown. While the rolls bake, make the icing by mashing softened cream cheese and powdered sugar together until smooth. Gradually whisk in buttermilk until the icing is creamy.
Once the rolls are done, drizzle the icing over the hot cinnamon rolls and spread evenly. Enjoy your delicious, yeast-free Cinnabon-style cinnamon rolls warm from the oven!