• Preheat oven to 170C/340F and get two 7" baking tins ready by greasing them and putting baking paper on them. In a bowl, mix self-raising flour, cocoa powder and baking powder well and keep it for later.
• In a different bowl, beat the butter for a minute. Add sugar to the bowl and beat the butter and sugar with a stand or hand mixer for 5 minutes until the mixture is light and fluffy.
• Break an egg and put it in the butter and sugar mixture, then beat well until the egg mixes well. Do this with all the eggs. Then, put half of the flour mixture and fold or whisk it with the egg mixture. Next, put half of the milk and mix it with the batter to make it smooth.
• Repeat the previous step and add the remaining half of the ingredients. Split the batter into the tins and bake the cakes in the oven that is already hot for 20-25 minutes. After 20 minutes (not before), check the cakes by putting a skewer in them. The cakes are done if the skewer is clean.
• Carefully take the cakes out of the oven and let them cool in the tins for 5 minutes before moving them to a cooling rack to cool down completely.

Pistachio Ganache

• Make the pistachio ganache while the cakes cool. In a bowl, mix white chocolate, heavy cream, almond extract (optional) and pistachio paste. Microwave in 30-second bursts, stirring well each time, until smooth and glossy. Or, heat the mixture in a bowl over a pot of simmering water, stirring now and then.
• Cover the ganache with plastic wrap, pressing it against the surface to prevent air bubbles. Let it cool and set for at least 2 hours at room temperature or in the fridge.
• Whip the set ganache for a few minutes, then pipe it onto the cooled cake.

Decorate Cake

• Put one cake layer on a plate or cake board and spread some ganache over it. Place the other layer on top. Frost the whole cake with the rest of the ganache and smooth it with a spatula. For a textured look, use a ridged spatula. Press chopped pistachios onto the bottom edge of the cake. Pipe some ganache around the top edge and dust cocoa powder over it.
• In a microwave-safe bowl, combine 100g of chocolate and a few drops of oil. Microwave in 30-second bursts, stirring well each time, until melted and smooth. Let it cool slightly, then drizzle it over the center of the cake. Sprinkle more chopped pistachios over the chocolate. Enjoy this delicious cake for dessert or on special occasions.