Make the Chocolate Cake

1. In a large mixing bowl, whisk together the eggs, sugar, vegetable oil, and vanilla extract until well combined.
2. In another bowl, sift together the flour, cocoa powder, baking soda, baking powder, and salt.
3. Add the buttermilk and hot coffee (or hot water) to the wet mixture, alternating with the dry ingredients. Mix gently until the batter is smooth and well combined.
4. Divide the batter evenly between three 6-inch (15 cm) cake pans lined with parchment paper at the bottom.
5. Bake in a preheated oven at 330°F (165°C) for about 40 - 45 minutes, or until a toothpick inserted in the center comes out clean.
6. Run a knife around the edges to loosen them, then remove from the pans and place upside down on a wire rack to cool completely. This helps keep the layers flat and even.

Make the Pistachio Kataifi Insert

1. In a bowl, mix pre-toasted kataifi with pistachio spread and a bit of green food coloring, if desired.
2. Line the bottom of two 5-inch (12 cm) cake rings or small pans with parchment paper.
3. Divide the mixture evenly into the two molds, press to smooth the tops, and freeze for at least 2 hours until firm.

Make the Chocolate Ganache Frosting

1. Chop semi-sweet chocolate and place in a heatproof bowl.
2. Heat heavy cream until just simmering, then pour over the chocolate.
3. Let sit 1 minute, then stir until smooth and fully melted.
4. Add cold heavy cream, then blend using an immersion blender until perfectly smooth.
5. Cover the surface with plastic wrap and refrigerate overnight.
6. The next day, whip the cold ganache with an electric mixer for about 1 minute, until thick and fluffy.

Assemble the Cake

1. Use a tall cake ring with an acetate sheet or a deep cake pan lined with plastic wrap for clean assembly.
2. Place the first cake layer at the bottom. Pipe a ganache border around the edge, fill the center with ganache, and add a frozen pistachio-kataifi insert in the middle.
3. Add the second cake layer, repeat the ganache and insert step, and finish with the third cake layer.
4. Chill the cake in the freezer for 30 minutes or the fridge for 1 hour to set before frosting.

Frost and Decorate

1. Remove the cake ring and acetate. Cover the cake with the whipped chocolate ganache, smoothing the sides and top with a spatula.
2. Chill again for at least 1 hour to set the frosting.
3. Make the drip by melting white chocolate with heavy cream, add pistachio spread and green food coloring.
4. Drizzle the green chocolate drip over the top edge of the cold cake, let it drip down the sides add some crushed pistachios, and chill the finished cake for at least 2 more hours before serving.