Melted butter, to grease, plus extra 250g, melted
250ml pink champagne or pink sparkling wine (at room temperature), plus extra 125ml
6 free-range eggs
1 Tbsp vanilla bean paste
2 cups caster sugar, plus extra ½ cup
4 cups self-raising flour
Pink food colouring gel, to tint
Fresh flowers (for decoration only, not for eating), we used David Austin roses, bachelor buttons, lisianthus, pink boronia and peppercorn foliage, to decorate
Pink Champagne frosting
375g unsalted butter, at room temperature
4½ cups icing sugar mixture
60ml pink champagne or pink sparkling wine (at room temperature)
1 tsp vanilla bean paste
Pink icing colour gel, to tint
Preheat oven to 160 degrees C fan-forced (180 degrees C conventional). Grease two 20cm round cake tins with butter and line bases and sides with baking paper.
Put champagne, eggs, vanilla and extra melted butter in a large bowl. Beat with a hand whisk until combined.
Pour in sugar and beat again with a whisk. Sift in flour, then beat again until a smooth batter forms. Divide batter in half.
Tint 1 batch of batter very pale pink and the other stronger pink, using food colouring gel.
Pour batters between prepared twins, smooth surface. Bake for 50 minutes, or until cooked when tested with a skewer. Cool cakes in tins for 15 minutes before turning out onto a wire rack to cool completely.
Meanwhile, combine extra champagne and extra sugar in a saucepan over a low heat, stirring until sugar has completely dissolved. Increase heat to medium and bring to the boil. Simmer for 4 minutes or until slightly thickened, then remove from heat and set aside to cool completely.
To make frosting, beat butter in a large bowl of an electric mixer with whisk attachment on high speed until light and fluffy. Gradually add sugar, ½ cup at a time, beating until smooth, light and fluffy. Add champagne and vanilla and beat again. Tint pale pink with a little icing colour gel and beat until colour is even.
Trim the top of the cooled cakes to level, then slice each in half horizontally using a serrated knife or cake leveller.
To assemble the cake, put the base piece of dark pink cake on a cake stand, cut side up. Brush with 1 heaped tablespoon of champagne syrup. Top with ¾ cup frosting, and spread to coat top.
Continue layering with cake (in alternating colours), syrup and frosting, finishing with soft pink cake on top.
Using a palette knife, spread remaining frosting over the top and side of cake to cover completely. Decorate centre of cake top with flowers and foliage, arranging them to cascade over side of cake. Serve.