In a small saucepan over medium-low heat, add ¾ cup milk and ⅓ cup softened unsalted butter. Stir until the butter has melted and remove from the heat. Let stand until lukewarm temperature.
In a large mixing bowl, whisk together 2 ¼ cups of the 3 ¼ cups all-purpose flour, 2 teaspoons instant yeast, ¼ cup granulated sugar, and ½ teaspoon salt.
Add the flour mixture to a stand mixer with the dough hook attached. Add 1 egg and ¼ cup water and start mixing on medium-low speed. Slowly add the milk mixture and remaining flour until the dough starts to form and becomes smooth. Let the dough rest for 10 minutes.
On a lightly floured surface, roll the dough into a large 9×15-inch square. About ¼-½ inch thick.
Filling
In a small bowl, combine 1 tablespoon cinnamon, ¼ teaspoon nutmeg, and ¾ cup packed brown sugar for the filling. Spread 5 tablespoons softened unsalted butter onto the dough, keeping it about a ½ inch away from the edge.
Sprinkle the cinnamon and brown sugar evenly over the top of the softened butter. Sprinkle with 1 chopped Granny Smith apple.
Roll up the dough from the long side into a log and pinch the seams. Cut into 9-12 slices, depending on how thick you want your cinnamon rolls.
Place in a greased 9×13-inch pan or 9-inch pie pan, cover with a damp cloth, and let rise for 30 minutes.
While the cinnamon rolls are rising, preheat the oven to 375 degrees Fahrenheit. Bake for 25 minutes or until the tops are golden brown.
Caramel Glaze
In a medium saucepan, melt ¼ cup unsalted butter, ½ cup brown sugar and ¼ cup sweetened condensed milk until the sugar dissolves.
Bring to a boil over medium-high heat for about 2-3 minutes. Pour over the warm cinnamon rolls.
Notes
Storing: Place in an airtight container or zip-top bag and store in the refrigerator for 2 to 3 days.
Freezing: Wrap each cinnamon roll individually in foil, then place in a freezer bag. Store in freezer for 1 to 2 months.
Reheating: Reheat in the oven at 350°F until warm for best results or microwave for 1 to 2 minutes.