Elderflower Cake

This one went down a storm with everyone who tried it, I'll certainly be making it again.  Credit for the recipe goes to Lynn Hill of the Clandestine Cake Club.
When choosing the elderflower cordial for this recipe, look at how much you have to dilute it to make a drink as they vary between one part cordial to four parts water, to one part cordial to ten parts water.  Obviously, you want to pick one which is very concentrated and which needs to be heavily diluted for a nice, intense flavour.

Equipment -
2 x 20cm round sandwich tins, greased and base lined
Electric whisk

Oven temp -
190C / Gas Mark 5

Ingredients -
Sponge -
4 large eggs, separated
230g caster sugar
2 tbsp elderflower cordial
130g SR flour

White Chocolate Ganache -
250g good quality white chocolate, finely chopped
250ml double cream

Elderflower Buttercream -
175g - butter, softened
175g - icing sugar
2 tbsp - elderflower cordial, or more to taste
Squeeze of lemon juice

Method -

Sponge -
1. Preheat oven to 190C.
2. Beat the egg yolks and 190g of the sugar using an electric whisk until mixture is light and fluffy and doubled in size (this may take 10 mins depending on how powerful your whisk is).
3. Mix in elderflower cordial.
4. In a clean bowl, whisk the egg whites until soft peaks form (make sure your beaters are properly clean too, any trace of grease will stop the maximum volume of air be whisked in).  Add remaining sugar and beat well.
5. Carefully fold half the egg whites into the yolk mixture, then sift in half the flour and gently fold that in too.  Repeat with the remaining egg white and flour.
6. Divide mixture between the two tins, spreading evenly.  Bake for about 25 mins, until a skewer inserted into the centre comes out clean. Leave to cool in the tin for a few mins, then turn out onto cooling racks and leaving to cool completely.

Ganache -
1. Place white choc in a bowl.  Heat the cream in a small pan until bubbling slightly round the edges.  Pour over the chocolate and stir until melted.
2. Cover with cling film a put in the fridge  until it has a soft spreading consistency.  (This may take around 4 hours)

Buttercream -
1. Beat the butter until light and fluffy, then gradually sift in the icing sugar and beat that in.
2. Mix in the cordial a little at a time, taste and a more if needed along with a squeeze of lemon juice.

To Assemble -
Sandwich the cakes with the buttercream, then spread the ganache over the top and sides.  Allow the icing time to set before slicing.