Melt the butter in a small saucepan, then remove it from the heat. Add the milk and pour it into the bowl of a stand mixer fitted with a dough hook. Measure the temperature to be sure it’s between 90F and 110F. If it’s hotter than  110F, allow it to cool so that it doesn’t kill the yeast. Sprinkle the yeast, then the sugar, over the warm milk and butter, then give it a stir to wet all of the yeast. Allow it to sit for five to ten minutes, or until the yeast is foamy. Lightly beat the egg in a separate bowl, then add to the milk & yeast mixture.

Add in the flour and salt and turn the mixer on low until the dough has come together into a ball. Turn the mixer up to medium and knead for 4-6 minutes, or until it is a smooth and taut. Remove the dough from the mixing bowl, shape the dough into a ball, and place it into a greased bowl. Allow it to rise for 1 -1 1/2 hours, or until doubled in size. At this point, you can use it to make a variety of sweet breads or rolls. Simply shape however you like, then cover with a cloth and allow to rise for about another hour, or until the dough is soft and puffy.

To Make the Rolls: While the dough is rising, mix together your filling in a mixing bowl. Make sure your butter is nice and soft so that it will spread easily over the dough without tearing it.

After the dough has risen, turn it out onto a well-floured surface. Roll into a rectangle 18″x24″ and carefully spread the filling in an even layer over the dough. Roll it along the long edge of the rectangle into a spiral. When you’ve rolled it up completely, pinch the edge to the roll of dough to seal it. 

Cut the roll of dough into 2″ sections, then place them in a greased baking dish. Cover lightly with a clean towel and allow the rolls to rise for about 45 minutes to an hour, or until the rolls have become puffy and soft.

While the cinnamon rolls are rising, preheat the oven to 350F/176C. When it’s ready, bake them for 25-30 minutes, or until the rolls are a light golden brown and are no longer doughy in the middle. Allow them to cool.

Frosting the Cinnamon Rolls:

With a hand mixer, beat together the butter, powdered sugar, 4 Tbsp. of the whipping cream, and vanilla until fluffy. Add the rest of the cream, on tablespoon at a time, until the frosting is the consistency you want. If you prefer a thinner frosting that seeps into the rolls, use milk instead of cream.