About a year ago, Maria sent Sophie and me a recipe she developed for buttermilk potato cinnamon rolls with the caption: "I created this recipe and I think they were bomb diggity!"
I love potato in breads. It adds this soft, fluffy dimension. The buttermilk's tang keeps this cinnamon roll recipe from veering too sickly sweet. Maria's original recipe keeps the butter at a neat stick, with 6 tablespoons in the dough, a tablespoon in the filling, and a tablespoon in the frosting. I found I wanted more oomph in my filling, so I bumped up the butter in the filling, cut it out of the frosting, and swapped the white sugar for more brown sugar--yielding a stickier swirl. You'll find both options in the recipe below.
Maria's original recipe was pretty barebones, since she dashed it off in a moment of inspiration in the kitchen. After some tinkering, I think I've been able to fill in all the blanks. For instance, I wasn't sure what sort of pan to use: a cookie sheet or 13x9-inch cake pan. After trying both ways, here's the verdict: If you want neat little independent rolls, with crustier edges, bake on the cookie sheet (pictured above). If you want super soft, super fluffy, super tall pull-apart rolls, bake in the 13x9-inch baking pan (pictured below). IMHO, the 13x9 is the way to go.
Buttermilk Potato Cinnamon Rolls
[For the Dough]
1/2 cup mashed potato, warm or at room-temperature (NOT cold)
6 tablespoons (3 oz) butter, melted and cooled
1/3 cup white sugar
1 1/4 teaspoon salt
1 cup buttermilk, at room temperature
2 1/4 teaspoon yeast
4 cups all-purpose flour, plus more for kneading
[For the Filling]*
4 tablespoons (2 oz) butter, melted
1 tablespoon flour
1 tablespoon cinnamon
1/2 cup brown sugar
[For the Frosting]
3 oz cream cheese, softened
1 cup powdered sugar
1 tablespoon buttermilk
1/2 teaspoon vanilla
Make the dough. In a large mixing bowl, stir together mashed potato and butter. Add sugar and salt and stir.
In a measuring cup, whisk together buttermilk and eggs. Whisk in yeast. Add wet ingredients to potato mixture and stir until combined.
Add 4 cups of flour and knead until elastic and smooth, adding additional flour by the tablespoon only as needed, up to 1/2 cup more. Don't add more flour than you need! Only add flour if it's too sticky to manage. The dough should be tacky and soft. Place in a greased bowl, cover with a towel or plastic wrap, and let rise in a warm place until it has doubled in size, about 1.5-2 hours. (I like to put my dough in the oven with the light on.)
Make the filling. In a small bowl, stir together melted butter, sugar, flour, cinnamon, and vanilla.
Shape the dough. Dump the dough out on a lightly floured surface. Pat it down and flatten out into a rough rectangle. (If making these the night before, you can flatten dough on a greased cookie sheet, cover with plastic wrap, and place in the fridge overnight. Take them out the next morning and continue on.)
With a lightly floured rolling pin, roll the dough out into a large rectangle, about the size of a cookie sheet. Spread the filling out over the rolled dough. Starting with the longest edge further from you, begin rolling the dough so that it forms a long log. With a sharp knife, cut the log into 12 slices.
Lightly grease a 13x9-inch baking pan. Place the dough slices in the prepared pan, cut side up. Cover with a towel or plastic wrap and let rise in a warm place until puffy, about 30-60 minutes (depending on whether the dough is cold from overnight, or the temperature of the room).
Bake. Midway through the second rise, preheat the oven to 375 degrees. Bake the rolls until golden brown, about 20 minutes.
Make the frosting. While the rolls are baking, whisk together cream cheese, powdered sugar, buttermilk, and vanilla. When the rolls come out of the oven, frost them. Enjoy!
*Maria's original filling: decrease butter to 1 tablespoon, and use half white and half brown sugar (so, 1/4 cup of each).