In a microwave safe measuring cup, heat the milk to 100°F / 38°C. Whisk in the yeast and the sugar. Set aside until the mixture begins to foam. (~5 minutes)
While waiting, add the flour, salt, egg, and butter to the bowl of a stand mixer fitted with the dough hook attachment. When the yeast mixture begins to foam, add it in to the rest of the ingredients.
Knead the dough on low speed for 1 minute to allow the ingredients to come together. Increase the speed to medium-high and knead for an additional 10 minutes, or until the dough passes the windowpane test
Once the dough is done kneading, butter the inside of the bowl, form the dough into a ball and place it back in the bowl. Cover the bowl with a towel and place it in a warm environment to rise until doubled in size (~1 hr.)
Cinnamon Coffee Filling
Before it’s time to roll out the dough, make the filling. In a small bowl, beat together the butter, coffee grounds, cinnamon and brown sugar until combined.
Assembly
Once the dough has doubled in size, punch it down to remove excess air. Transfer the dough to a clean and lightly floured work surface.
Roll the dough out into a 14” x 12” rectangle. Carefully spread the cinnamon coffee filling over the dough
Tightly roll up the dough into a cylinder starting from the longer (14”) side. Use a sharp knife to slice the roll into 8 even rolls.
Place the rolls evenly spaced out in a buttered 9” cake pan or pie dish. Lightly cover the pan with a towel, and let the rolls rise in a warm environment until doubled in size (~30min.)
Preheat the oven to 350°F / 175°C. Once the rolls have doubled in size, brush the tops with heavy cream.
Bake the rolls for 20-25 minutes, or until the tops have turned golden brown.
Coffee Glaze
Whisk together the powdered sugar, salt, and freshly brewed coffee.
Pour the glaze over the cinnamon rolls, serve, and enjoy