Warm 1/2 cup of whole milk until lukewarm, then sprinkle 2 teaspoons of yeast over it and let sit for 5 minutes until frothy.

In a bowl, whisk together the yeast mixture with 1 large egg and 2 tablespoons of melted butter, then gradually add 2 cups of all-purpose flour, 1/4 cup of brown sugar, and 1/2 teaspoon of salt until sticky dough forms.

Transfer the dough into a lightly oiled bowl, cover with a damp cloth, and let rise in a warm area for about 1 hour.

Prepare the filling by mixing together 1/2 cup of pistachio butter, 1/4 cup of brown sugar, and 1 tablespoon of ground cinnamon until smooth.

Roll out the risen dough into a rectangle, spread the filling, roll tightly, and slice into 4 to 6 pieces.

Place the rolls into a greased baking dish, cover, and let rise for 30 to 45 minutes.

Preheat oven to 350°F (175°C) and bake the rolls for 23 to 30 minutes until golden brown.

Prepare icing by mixing cream cheese, powdered sugar, vanilla extract, and heavy cream until smooth.

Allow rolls to cool for 10 minutes before icing and serve warm.