Warm 1/2 cup of milk to about 110°F (43°C). Combine the warm milk and 2 teaspoons of active dry yeast; let sit for 5 minutes until foamy.

Whisk in 1 egg and 2 tablespoons of softened unsalted butter. In another bowl, mix 2 cups of all-purpose flour, 1/4 cup of sugar, and 1/2 teaspoon of salt. Gradually incorporate flour mixture until a sticky dough forms.

Knead the dough on a floured surface for about 5 minutes until smooth.

Place the kneaded dough in a greased bowl, cover, and let rise for about 1 hour, or until doubled in size.

In a bowl, mix together 1/2 cup of pistachio butter, 1/4 cup of brown sugar, and 1 teaspoon of ground cinnamon.

After the dough has risen, punch it down and roll it into a 12x9-inch rectangle. Spread pistachio filling evenly, then roll tightly from one long side.

Slice the log into 4-6 equal pieces and place in a greased baking pan to rise for 30-45 minutes.

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

For the icing, beat together 4 ounces of cream cheese, 1 cup of powdered sugar, 1 teaspoon of vanilla extract, and 2 tablespoons of heavy cream until smooth.

Spread icing over warm rolls and garnish with chopped pistachios.