Brown the butter: Melt butter over medium heat and cook, stirring often.The surface will look foamy and make sizzling sounds. The butter is ready when the sizzling has mostly stopped, and you notice brown specks at the bottom of the pan and a deep nutty aroma. Pour the browned butter into a glass container and set it aside to chill for 10 minutes.
Process the pistachios in a food processor until finely ground, and slightly moist.
In a large bowl, use a whisk to mix the cream cheese and soften it.
Add the ground pistachios, followed by the browned butter, and mix until fully blended and cohesive.
Use a rubber spatula to scrape the bottom and sides of the bowl and pile the mixture at the center of the bowl. Cover with a plastic bag tight on the surface.
While you wait, preheat your oven to 375F and grease a 9x5-inch loaf pan and line it with parchment paper.
Add the oil, milk, eggs, and sugar to the cream cheese-pistachio mix and mix until completely blend.
In a medium bowl, mix the flour, baking powder, baking soda and chopped pistachios.
Add the dry ingredients into the cream cheese mixture and mix just until you no longer notice and dry mixture. Do not over mix, a few lumps are ok.
Transfer the batter to the prepared pan and bake for 15 minutes, then reduce the oven temperature to 350F and bake for additional 40 minutes. Until a toothpick comes out from the center of the cake with a few moist crumbs.
Remove from the oven and let the bread set and chill in the pan for about 20-30 minutes before slicing and serving.