Sift the flour, baking powder and sat together in a bowl and set aside. Using an electric mixer cream the butter with 200g of the sugar until light and fluffy. Add the flour mixture and sparkling wine alternately mixing to a smooth batter. In a separate bowl beat the egg whites until stiff then gradually beat in the remaining sugar till you have a stiff meringue. Fold half the meringue into the batter mixing through gently then fold in the remaining meringue. Spray 2 x 20cm loose-bottomed cake pans with cooking spray and line the bases with bake paper. Divide the batter between the pans and bake in a preheated oven of 180 degrees C for 25-30 minutes. Allow to stand for 10 minutes before turning out onto a cooling rack.
For the filling combine the butter, marshmallows and wine in the top of a double boiler. Set over simmering water and stir until marshmallows have melted. Remove from the heat and stir in the coconut. Cool until thick enough to spread and use to sandwich the cakes together.
For the icing place the icing sugar, corn syrup and water in the top of a double boiler. Set over simmering water and stir until smooth. Add salt, vanilla and almond essence. Stir in food colouring – start with one drop. Spread the warm icing over the cake and decorate with the marshmallows.