Begin by baking the vegan chocolate cake according to your chosen recipe. If using a gluten-free flour blend, ensure it is well-mixed. Bake at 350°F (175°C) for approximately 25-30 minutes, or until a toothpick inserted in the center comes out clean. Once done, remove from the oven and let it cool completely in the pan.

While the cake cools, pour the chilled vegan heavy cream into a mixing bowl. Using an electric mixer, whip on medium speed until soft peaks form, which should take about 3-5 minutes. Then, gently fold in melted vegan chocolate until evenly combined.

Once the cake has cooled, carefully transfer it to a springform pan, ensuring it sits evenly. Pour the mousse over the cake layer, spreading it smoothly with a spatula. Next, refrigerate for at least 3 hours.

After the mousse has set, melt the vegan chocolate chips and a splash of vegan heavy cream in a microwave-safe bowl in 30-second intervals, stirring until smooth and glossy.

Pour the ganache over the chilled mousse layer and return the cake to the refrigerator for an additional hour to set the ganache.

When ready to serve, gently release the cake from the springform pan, slice, and present chilled, garnished with fresh berries or cocoa powder.