Preheat oven to 180°C/170°C fan/Gas Mark 4. Grease and line two 20cm (8 inch) round cake tins. Cream the butter and sugar until really pale and fluffy. Add the eggs one at a time and Vanilla Extract whilst beating until the mixture thickens up. Sift in the flour and Cocoa Powder and mix until all combined.

Divide the mixture evenly between the 2 tins. Bake for 25-30 minutes or until a cocktail stick comes out clean.

To make the edible glass shards, bring 250g of caster sugar and 125ml of water to a boil in a small high-sided saucepan, stirring, until sugar dissolves. Reduce heat to medium-high, and cook until the mixture just starts to turn pale gold around edges. Remove from the heat, and immediately pour onto a rimmed baking tray. Working quickly, tilt the baking tray to spread the mixture to edges to make a very thin layer. Let it cool and harden.

Beat the butter in a bowl until soft. Gradually sift and beat in the icing sugar and cocoa powder. Add the Vanilla Extract and enough milk to make the icing fluffy and spreadable.

Remove the cakes from the tins once cool. Carefully trim the rounded top off one cakes and slice each cake in half. Spread 3 cake rounds with chocolate buttercream and sandwich all the cakes together. 

Spread a thin layer of chocolate buttercream around the sides and on the top of the cake with a pallet knife. Make sure this is a really thin layer so scrape off any excess and put the cake into the fridge for about 30 minutes to harden.

Roll the Fondant into a large circle around half a cm thick - make sure you add icing sugar to your work surface and rolling pin so the icing does not stick. Remove the cake from the fridge and place the fondant on top, smoothing in upward motions with the palm of your hand - try not to use your fingers as this can dent the fondant. When the fondant touches the cake board, cut around the edge of the cake with a small sharp knife.

For the finishing touches, mix some Food Colour Gel with a small amount of water to make a red liquid. Cut some large slash marks into your cake using a small sharp knife, then trickle some red liquid in each slash until it pours out. You can also add some splashes of red colour by dipping a pastry brush and flicking this directly onto the cake. Break the glass into shards and place in the top of the cake.