Melt the butter in a small saucepan over medium-low heat, stirring and scraping the pan every 10-15 seconds.

The butter will melt, foam, then turn golden brown with nutty aroma and small brown bits (about 5-7 minutes).

Remove from heat and add cocoa powder and milk or dark chocolate bar in hot butter.Mix thoroughly till there're no lumps in it and set it aside to cool.

Preheat the oven at 166C if you're using dark colour aluminum pan or at 176C if using lighter colour aluminum pan.

Line a square 8 inch baking tin with parchment paper, leaving overhang for easy removal. Lightly grease the paper.

In a bowl add eggs, white sugar, light brown sugar, whisk together until most or all of the sugar granules have dissolved. This step is essential for achieving that shiny, crinkly top.

Once the sugar has dissolved, add the brown butter, cocoa powder, melted dark or milk chocolate mixture and vanilla extract. Mix everything together.

Add the all-purpose flour and salt and mix just until combined, avoid overmixing.

Fold in the chocolate chips or chunks until evenly distributed.

Pour the batter into the prepared pan and bake for about 30-40 minutes.

Begin checking at the 25 minute mark by inserting a knife into the center. The brownies are done when the edges are set and the knife comes out with a little batter still clinging to it. Depending on your oven, total bake time may be up to 40 minutes.

Let them cool down when they're done baking.

While the brownies are baking/cooling, start toasting the kadayif pastry. chop the pastry into small pieces, then heat up a pan over low-medium heat. add butter to the pan, and let it melt.

Add the chopped pastry to the pan and toast it in the butter over low-medium heat until it turns a golden brown colour.

Once the pastry looks golden brown and toasted, remove it from the pan and place it in another bowl. let it cool completely.

Now prepare the ganache. Add the cream and chocolate to a microwave safe bowl, and microwave in 15-20 second increments, stirring in between, until the mixture is warm and the chocolate has almost melted.

It should continue to melt in the next 1-2 minutes. If it isn't fully melted, microwave for another 10-15 seconds.

Cover the bowl with a plate and let it rest for sometime till it's warm and it's not hot.

Once the brownies and the kadayif pastry have cooled completely, start assembling the layers. warm the pistachio cream in the microwave (don't make it hot) until it's a pourable consistency, then add this to the bowl with the toasted pastry.

Add the tahini to the pastry as well, and mix everything together until the pastry is completely coated.

Add the pistachio filling on top of the brownies and smooth it out into a thick and even layer.

Pour the slightly warm chocolate ganache over the pistachio filling.

Tilt the dish around so that the chocolate can spread into an even layer, then place the brownies in the fridge for about 20-30 minutes so that the ganache can set.

Let the brownies sit out at room temperature for a while before serving, and make sure you dip a sharp knife in hot water to get those neat cuts, slice up and enjoy.