Prepare a stiff-peak French meringue using the egg whites and caster sugar. Gently fold in the egg yolks and vanilla extract. Fold in the sifted flour and cornstarch.
Oolong Syrup
Bring the water and sugar to a boil, then whisk in the oolong tea leaves.
Oolong Crème Brulee
Cook the leftover oolong tea leaves, whipping cream, milk, egg yolks, and caster sugar together until the mixture reaches 83°C. Strain out the tea leaves and incorporate the gelatin mass.
White Peach Confit
Mix the pectin, caster sugar, and dextrose in a bowl. Warm the fruit purees and glucose syrup in a saucepan to 45°C. Whisk in the pectin mixture and bring the entire mixture to a boil.
Peach Tea Mascarpone Chantilly
Bring the milk and peach tea leaves to a boil, then strain out the leaves. Incorporate the glucose syrup, inverted sugar, vanilla bean, and gelatin mass into the hot milk. Cool the mixture to 36°C and emulsify well with a Micromix. Incorporate the second portion of whipping cream and the mascarpone, then emulsify again. Store in the chiller for later use.
Assembly
Pipe a thin layer of whipped peach tea mascarpone chantilly onto the biscuit. Layer with oolong tea crème brûlée, followed by another layer of chantilly. Add the white peach confit. Pipe chantilly around the sides of the insert, then use a hard plastic scraper to smooth and curve the cream. Freeze the cake. To finish, pipe another layer of chantilly onto the sides and use the hard plastic to create the final design. Decorate with fresh white peach and dried cornflowers.