Grease 4 x 20cm/8inch sandwich tins and line the bottom of the tins with a round of baking paper or dust with flour.
In a large mixing bowl or a food mixer, beat the eggs with the sugar until creamy, light and fluffy.
Remove from the food mixer, and sieve in the flour and baking powder. Gently fold until fully combined. Separate the batter in 2 bowls and stir in the food colouring in each of the separate bowls. Pour the batter into the prepared sandwich tins.
Bake for 25-30 minutes or until a skewer inserted in the centre comes out clean. Remove from the oven and transfer to a wire rack. Allow to cool.
Next, prepare the butter cream. In a mixing bowl, beat the soft butter with the icing sugar and vanilla paste until light and fluffy.
Layer the first coloured cake onto a small plate with white butter cream. Repeat the same step until the 4 cakes are staked together. Cover the top cake and the sides with a final layer of buttercream. Smooth well using a warm spatula. Place in the fridge to set.
In the meantime, prepare the chocolate sauce. In a saucepan, bring to the boil the cream, honey and butter. Remove from the heat and whisk in the chocolate pieces until completely melted. Set aside until cool enough to drizzle on the cooled cake.
Pour all around to create scary icicles by carefully pouring a tablespoon at the time of sauce over the edges. Decorate with extra scary items such as ghostly marshmallows!
Keep aside until ready to serve, loosely cover with parchment or foil to allow the icing to create a lovely crust!