In a saucepan over medium heat, add milk and butter. Stir until melted and remove from heat.
In a mixing bowl, combine 2¼ c flour, sugar, salt. Add yeast and lukewarm milk mixture. Combine. Add egg & mix.
Using the dough hook attachment on your mixer, knead while gradually adding in 1 cup flour until the dough forms a ball and pulls away from the edges of the bowl. You can also knead by hand.
Let dough rest for 10 minutes. Preheat oven to 350 degrees.
On a floured surface, roll out dough into a rectangle. Spread melted butter on top. Combine cinnamon and sugar and sprinkle on top. Using a knife or pizza cutter, cut 10 strips. Roll each end of a strip toward one another until they touch. Turn it on it's side.
Gently pull down the bottom of the dough with your finger to slightly stretch.
Lightly pinch the bottom of the heart and place into a greased bread pan.
Turn oven off. Cover rolls with a damp towel and allow to rise 25 minutes. Remove from oven, preheat again to 350 degrees. Bake 10-12 minutes, or until slightly golden.
Mix icing ingredients until smooth and drizzle over rolls.
Butter your baking dish before adding the rolls to it, so that once baked they are easy to remove and won’t stick.
You can bake these rolls ahead of time and keep them covered in the fridge. Gently reheat them in the oven and spread over the frosting before serving.
Leftovers can be stored in an airtight container and kept in the fridge for 3 days. They can be eaten cold or warm them in the oven or microwave.
For a thinner icing, add a little extra milk when mixing the frosting.