Proof your yeast by mixing warm water, yeast, and 1 tsp sugar in a cup or bowl. Let sit for 10 minutes until bubbly.

Warm milk and melt 1 cup butter. Pour into a large mixer bowl and add proofed yeast and beaten egg. Mix flour, sugar, and salt separately, then slowly add to wet ingredients. Knead with dough hook or hands for a few minutes until smooth and pulling away from bowl sides.

Form dough into a ball, place in a bowl, cover with a towel, and let rise for 1-2 hours until doubled. Meanwhile, prepare filling by mixing ½ cup butter, brown sugar, and cinnamon in a bowl until smooth.

Punch down risen dough and place on floured surface. Form into a ball. Keep as one dough for 12 large rolls or cut in half for 24 rolls.

Roll dough into a large rectangle and spread filling evenly over surface. Roll tightly and cut pieces using floss or string.

Preheat oven to 350°F. Place rolls in a greased 9x13 baking dish, cover with towel, and let rise 20-30 minutes. Alternatively, refrigerate overnight and remove 1-2 hours before baking.

Pour heavy cream over rolls and bake for 25-35 minutes until tops are lightly golden (16-20 minutes for smaller rolls).

While rolls bake, make frosting by mixing room temperature butter and cream cheese until combined. Sift in powdered sugar and mix. Add vanilla and mix again.

Allow baked rolls to cool at least 30 minutes before frosting. Frost and serve.