- Preheat oven to 180°C and grease and line two 15cm cake tins.
- Pour the melted butter into a bowl or stand mixer bowl with the sugar, zest and vanilla, and beat (with the beater attachment on the mixer or a spatula) until fully incorporated.
- Mix in the eggs. Add the flour and slowly mix until the batter is smooth.
- Divide the batter evenly in the tins (roughly 475g in each)
- Bake for 40-45 mins until the sponge is cooked through and bounces back at the touch.
- Cool in the tins for a couple of minutes then remove to a wire rack to cool completely.
- Heat up the cream until steaming and place chocolate in a heat proof bowl.
- Pour over the chocolate and mix until the chocolate is melted and smooth. Allow to cool slightly before using on the cake.
- Cut the top off both cakes and halve each cake horizontally. Put a cake board on a turntable and spread out a bit of buttercream.
- Take one of the bottom cake layers and centre it onto the board facing up.
- Spread or pipe a layer of buttercream, half the thickness of the layer of cake.
- Add the next layer of cake and repeat the process, saving the other bottom layer of cake for the top and face it downwards so the top is flat.
- Using a palette knife and scraper, coat the cake in buttercream and scrape away any excess, making sure the sides are straight and top flat.
- Refrigerate for 30 minutes (or freeze for 10 minutes) until the buttercream’s firm.
- Colour the remaining buttercream and apply around the sides and top of the cake, smoothing out with the scraper.
- Pour cooled ganache over the top of the cake and spread until it reaches the sides, gently nudging it so it drips down.
- Leave to set for about 10 minutes and use the remaining buttercream stick all your decorations on top.
For the cake
To assemble the cake: