Preheat the oven to 425F. Butter a round 10" pan and set aside.

To prepare the filling, combine all sugar and spices in a bowl. Mix to combine and then add the 2 tbsp of melted butter. Mix together until it resembles sand. Set aside.

Prepare the dough by add all the dries in a mixing bowl. Mix to evenly distribute the ingredients. Combine the buttermilk and 2 tbsp of melted butter. Add the wet ingredients to the dries and mix just until it comes together to form a shaggy dough. Transfer the dough to a floured work surface.

Knead the dough just until it forms a smooth ball.

Press the dough into a 12" x 9" rectangle. Spread the 2 tbsp of softened butter over the dough while leaving a 1/2" border. Spread the sugar filling evenly over the dough. Press the mixture in with your fingers of with a rolling pin.

Roll the dough into a log from one long end of the rectangle. Press the seams together at the end. Using a string of sharp knife, cut the log into 8 pieces. Gently open and flatten the cut side of the bun and transfer it to the prepared pan.

Bake for 25 minutes or until golden brown. Meanwhile, prepare the icing by combining all the ingredients in a bowl. Mix together just until smooth.

When the cinnamon buns are out of the oven, you have a choice to either leave it in the pan or you can flip it out onto a plate. Be careful not to burn yourself! Let the buns cool for 5 minutes and then drizzle on the icing. Serve warm.