Preheat your oven to 350°F (175°C) and grease a round cake pan.

In a bowl, whisk together the flour, cocoa powder, baking powder, and baking soda.

Stir in the sugar, vanilla essence, oil, and water until the batter is smooth.

Pour the batter into the prepared pan and bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cake to cool completely before assembling.

In a large bowl, beat the whipping cream until soft peaks form.

Gradually add the powdered sugar and cocoa powder, continuing to beat until stiff peaks form.

Refrigerate the mousse until you’re ready to assemble the cake.

Heat the cream in a small saucepan over medium heat until it begins to simmer.

Remove from heat and add the chopped dark chocolate. Let it sit for a minute, then stir until smooth and glossy.

Allow the ganache to cool slightly before pouring over the cake.

Place the cooled chocolate cake on your serving plate.

Spread the chocolate mousse evenly over the top of the cake.

Pour the chocolate ganache over the mousse, allowing some to drip down the sides.

Sprinkle grated dark chocolate over the ganache for a decorative finish.