Add kataifi to a large nonstick skillet. Bring to medium low heat on the stove, stirring constantly until all of the kataifi becomes toasted and golden brown in color. Set aside to allow to cool.

Preheat oven to 350°F (177°C). Line an 8 x 8 inch pan with parchment paper.

In a large microwaveable bowl, add chocolate chips. Heat in 15-30 second intervals, stirring in between with a spatula, until chocolate is completely melted and smooth. You can also melt the chocolate on the stove using the double boiler method.

Add in the room temperature egg whites. It is important that your egg whites are room temperature because if they are too cold, they will cause the chocolate to seize. Vigorously whisk in the egg whites until they are completely incorporated with the chocolate and you have a smooth batter. You want to whisk vigorously to break up the egg whites completely. To make sure your egg whites are fully mixed in, lift your whisk a few times and the batter should fall evenly and smoothly, with no visible clumps or traces of egg.

Pour batter into prepared pan. Bake for about 13-15 minutes or until done. When brownies are done, the surface should look shiny, crinkly and cracked. The brownies may also be raised quite high (it will sink back down when you remove them from the oven). When you insert a toothpick, the brownie batter should not be liquid but also should not come out clean. What sticks to your toothpick should look like moist fudgy crumb. The brownies bake very quickly so keep a close eye on them during the last few minutes of baking.

Allow the brownies to cool and deflate a little. While the brownies are cooling, add toasted kataifi and pistachio cream to a medium mixing bowl and stir until evenly combined. Your mixture should be like a thick creamy paste that isn't too runny.

Gently spread the pistachio mixture over the still warm brownies. I use an offset spatula to help spread the pistachio mixture evenly across. Allow the brownies to cool so that the fudgy chocolate layer has a chance to set and firm up.

After the brownies are fully cooled, you can add an optional chocolate frosting on top of the brownies. You can either spread melted chocolate on top for a firmer chocolate layer on the brownies, or you can add melted coconut oil with the melted chocolate for a soft chocolate layer on top. You can also mix chocolate with heavy cream for a chocolate ganache layer on top. See notes for more details.

Cut the brownies with a large sharp knife, wiping the blade in between each cut. Uneaten brownies can be stored for 1 day at room temperature and longer in the fridge or freezer.