Elderflower And Prosecco Cake

Preheat the oven to 350u0b0F. Grease a 10 inch diameter spring-form pan and sprinkle with flour. Beat the egg whites and 3 tbsp water until forming stiff peaks, gradually adding the sugar, 1 tsp vanilla extract and a pinch of salt. Beat in the egg yolks one at a time. Sift in the flour, cornstarch and baking powder and fold in. Spoon into the pan and smooth out. Bake for 25-30 mins, until a skewer comes out clean. Allow to cool for 2 hours.
Turn cake out of the pan and cut in half horizontally by inserting a knife into the center and rotating the cake around it. Place the bottom cake on a cake plate and place a cake ring around it. Spread with jam.
Soak the gelatine according to package directions then dissolve in a saucepan over a low heat. Stir in the elderflower syrup, then the prosecco. Chill for 20-30 mins, or until the mixture begins to set, stirring occasionally. Whip 1 2/3 cups cream until forming stiff peaks and fold half into the prosecco mixture. Chill for 5 mins, then fold in the remaining cream. Spread over the jam layer, then press the second cake lightly on top. Chill overnight.
Whip remaining 1 1/2 cups cream and 1 tsp vanilla extract until forming stiff peaks. Remove the cake ring and spread two-thirds of the cream over the top and sides of the cake. Press the pistachios around the edge. Spoon the remaining cream into a piping bag fitted with a medium star nozzle and pipe tufts of cream over the top of the cake. Decorate with sugar flowers.