In a saucepan over medium heat, melt the fresh whipping cream, dark chocolate, and salted butter until the mixture is silky and smooth.
Once melted, strain the mixture through a sieve and stir in the two teaspoons of vanilla extract.
In a separate bowl, combine the icing sugar and cocoa powder, then pour the melted chocolate mixture into this bowl and mix until smooth.
Transfer the chocolate fudge mixture into a dish, pressing it down to create an even surface, and refrigerate it.
In another bowl, mix together the plain flour, unsweetened cocoa powder, bicarbonate of soda, baking powder, granulated sugar, and soft dark brown sugar.
Add the large eggs, sunflower oil, salted butter, two teaspoons of vanilla extract, and buttermilk to the dry ingredients, mixing well to combine.
In a separate bowl, mix the boiling hot water with coffee powder, then add this mixture to the cake batter to activate the baking soda and baking powder.
Prepare three cake tins and preheat the oven to 175 degrees Celsius.
Evenly pour the cake batter into the prepared cake tins and bake until fully cooked.
After baking, allow the cakes to cool before assembling.
Remove the parchment paper from the cakes and layer them with chocolate fudge in between each layer, smoothing it out with a pallet knife.
