Preheat the oven to 350°F (175°C). Grease a 9-inch (23 cm) round cake pan and line it with parchment paper.

In a large mixing bowl, combine the flour, cocoa powder, sugar, baking powder, baking soda, and salt.

Add the eggs, milk, vegetable oil, and vanilla extract. Mix gently until smooth.

Slowly add the hot coffee or hot water and continue mixing until combined.

Pour the batter into the prepared cake pan and bake for 30–35 minutes, or until a toothpick inserted in the center comes out clean.

Remove the cake from the oven and let it cool completely.

Beat the cream cheese and powdered sugar until smooth and creamy.

Add the vanilla extract, whipped cream, and crushed pistachios. Mix gently until combined.

Spread the pistachio topping evenly over the cooled cake.

Decorate with chopped pistachios, chocolate shavings, and an optional drizzle of melted chocolate. Slice and serve.