Prepare the dough. In a large bowl, whisk together flour, sugar, and salt then set aside. Combine the milk and butter together in a small bowl then warm in the Microwave or stove until the butter melts. Whisk in the yeast until it dissolves. Pour this mixture into the dry ingredients, add the egg, and stir or use a stand mixer with a paddle attachment until a soft dough forms.

On a lightly floured surface, knead the dough for 3-5 minutes, forming a smooth ball. Add a little flour if it’s too soft or sticky. Place in a lightly greased bowl, cover with a clean dish towel, and let the dough rest. Meanwhile, prepare the filling. Coarsely chop the pistachios in a food processor. Mix together the cinnamon and brown sugar.

After 10 minutes, roll the dough out to roughly a 14x8-inch rectangle. Spread the softened butter on top then sprinkle the surface with the cinnamon and brown sugar mixture. Do the same with the chopped pistachios. Roll the dough up length-wise into a 14-inch log and cut into 10 or so even rolls. Arrange in a greased 10-inch round cake pan or square baking pan. Leave room between. Cover with a clean dish towel and set the pan in a warm spot for 60-90 minutes.

While the rolls rise, make the Pistachio Cream. Removing the skins of the pistachios by boiling for a few minutes then rubbing with a dishtowel will bring out the green color. But it’s just as tasty if this step is skipped. Add pistachios, milk and 1 tablespoon of powdered sugar to a food processor. Blend for around 5 minutes until the pistachios turn into a smooth paste, scraping down the sides every minute or so. Heat butter and white chocolate in a saucepan until melted. Scoop the pistachio paste into a blender and then pour in the melted white chocolate mixture then blend until smooth.

Heat the oven to 375°F. Once the rolls double in size, bake on the middle rack for 25 minutes, or until lightly browned. Remove from the oven and place the pan on a wire rack to cool slightly.

While the rolls are still warm, not hot, spread over the Pistachio Cream with a knife or icing spatula. Cover any leftovers tightly and store at room temperature.