Preheat the oven to 350 degrees F. Grease a 9×9 square pan with nonstick spray, then add a layer of aluminum foil that hands over two sides and grease it again.
In a heat-safe bowl or measuring cup, melt a sick of butter in 30-second increments. Ain the chocolate pieces, vanilla extract, espresso powder, and salt. Stir well until all is melted and well combined.
In a large bowl, combine the sugar and brown sugar. Pour in the chocolate mixture and whisk together. Add the eggs one at a time, mixing each one until well incorporated. (This makes the top layer shiny.)
Add the flour and cocoa powder and fold until just incorporated. Transfer the batter to the prepared pan and transfer it to the oven. Bake for 22-25 minutes or until a toothpick comes out clean when inserted in the center.
Allow the brownies to cool completely before removing them from the pan and slice them into squares.
In a large pan over medium heat, melt butter then add in the chopped kataifi. Cook until it becomes a golden brown color, stirring frequently, about 10-15 minutes.
Transfer the kataifi to a bowl and combine it with the pistachio butter, tahini, and a pinch of salt. Spread the kataifi mix in an even layer over the brownies. Use a spatula to ensure it is nice and smooth.
Melt chocolate in a heat-safe bowl or cup in the microwave in 30-second intervals. Pour the melted chocolate on top of the kataifi layer so that it is smooth and well-covered. Immediately garnish with chopped pistachios and flakey salt before the chocolate sets.
Allow the top chocolate layer to cool completely. Then, slice, serve and ENJOY!
