Dough:
10 Ounces Buttermilk, room temperature
3.25 Ounces sugar
1 teaspoon Salt
2.75 Ounces Butter, room temperature
1 Egg, slightly beaten
16 Ounces Flour (all-purpose or bread flour works)
2 teaspoons instant yeast
Filling:
2 Tablespoons butter, melted
1/2 C Sugar
1 1/2 Tablespoons Cinnamon
1 C Raisins (optional)
Glaze:
2 C Powdered Sugar
2 Tablespoons Butter, Melted
1 teaspoon vanilla
1 - 3 teaspoons Milk
In the bowl of a mixer fitted with a dough hook, combine buttermilk, sugar, salt, butter and egg. Mix on low for 30 seconds, just to combine.
Add flour on top of wet ingredients and then yeast on top of the flour. Mix on low until combined then knead for 4 - 5 minutes. You may need to add additional flour to make a manageable dough - use as little as possible but you don't want it to be too sticky or it will be difficult to work with.
Turn dough out into a bowl and cover - allow to rise till doubled, about 1 to 1 1/2 hours. Gently deflate the dough and roll out into a rectangle roughly 16 inches by 12 inches. Brush the dough with the melted butter.
In a small bowl, combine sugar and cinnamon then sprinkle over the dough. Sprinkle with raisins, if desired. Starting from the long edge, roll dough up into a log and pinch to seal. Cut the log into 12 even pieces and place on a parchment-lined baking sheet about 1/2 inch apart. Cover and allow rolls to rise until dearly doubled, about 1 hour.
During the last 15 minutes of rising time, preheat the oven to 350 degrees. Bake the buns for 15 - 20 minutes, until lightly browned then cool on a wire rack for at least 20 minutes before serving.
Make the glaze by combining the powdered sugar, butter, and vanilla. Mix to combine and add milk as needed to make a thick icing. Frost the rolls and enjoy!