These delightfully tender sweet rolls combine the best of two well-loved treats: cinnamon buns and apple pie. The jammy apple filling, scented with cinnamon, is swirled inside a buttery crust. One bite will have you wondering why cinnamon rolls haven't always included this delicious filling!
To make the dough: Whisk together all of the dry ingredients, then add the butter, vanilla, egg, and milk, mixing until a shaggy dough forms. If you're using mashed potatoes add them along with the wet ingredients.
Knead the dough — by hand, using a mixer, or in a bread machine set on the dough cycle — until it's smooth and soft, though still slightly sticky.
Place the dough in a greased bowl, cover the bowl, and let the dough rise until it's almost doubled in bulk, about 1 1/2 to 2 hours. While the dough is rising, make the filling.
To make the filling: In a medium saucepan, toss the grated apple with the lemon juice.
Whisk together the sugar, cornstarch, salt, and cinnamon and add to the pan, stirring to combine.
Cook the apple mixture over low heat, stirring frequently, until the apple starts to release its juice. Increase the heat to medium and bring to a simmer.
Simmer, stirring, until the mixture thickens, 1 to 2 minutes; drawing a spatula across the bottom of the pan should leave a track that doesn't readily fill in. Remove from the heat and set aside to cool to room temperature; if you want to hasten the process, place in the refrigerator.
To assemble the rolls: Gently deflate the risen dough and turn it out onto a lightly floured or greased work surface. Divide the dough in half.
Roll the first half into a 10" x 12" rectangle. Spread half the filling over the rolled-out dough, leaving a 1/2" margin clear of filling along all sides. If adding chopped nuts, sprinkle them evenly over the filling.
Starting with a long side, roll the dough into a log, sealing the edge by pinching it shut. Repeat with the second piece of dough.
Score each log into 12 equal pieces, about 1" for each slice. Cut the dough at the score marks. Dental floss will give you the cleanest cut: pull off a long piece of floss, loop it underneath the log at the score mark, and pull the ends in opposite directions to cut the dough. If you don’t have dental floss, a bench knife or sharp knife will work. Repeat until you've cut all of the rolls.
Place the rolls cut side up in the well-greased or parchment-lined pans of your choice. Place them close together in a 9" square pan for soft-sided rolls, or on a baking sheet about 2" apart for crustier rolls.
Cover the rolls and let them rise until they're puffy, about 1 to 2 hours. Toward the end of the rising time, preheat the oven to 350°F.
To bake the rolls: Uncover the rolls and bake them for 18 to 20 minutes, until they're lightly browned. When the rolls are fully baked a digital thermometer inserted into the center of one of the rolls (be sure to position the thermometer in the bread, not the filling) should register about 190°F.
Remove the rolls from the oven and allow them to cool slightly while you make the glaze.
To make the glaze: Mix together all of the glaze ingredients, starting with the lesser amount of cream. Add additional cream as necessary to make a thick but pourable glaze.
Drizzle the glaze over the rolls and serve.
Storage information: Store leftover rolls, loosely covered, at room temperature for several days.
