Preheat oven to 200°C. Grease and line a shallow 16cm x 26cm baking tray and set aside.
For the Sponge Cake, combine eggs and sugar in the bowl of a stand mixer fitted with a paddle attachment and beat until light and fluffy. Sift flour over the mixture, then gently fold the flour through the mixture until combined. Gently fold the butter through the mixture until combined.
Pour the cake batter into the pre-lined baking tray. Place into the oven to bake until golden and a skewer comes out clean when inserted, about 15-17 minutes. Remove from the oven and set aside to cool.
For the Vanilla Cherries, combine all ingredients in a small saucepan over low heat and cook, stirring occasionally, until reduced to a syrup consistency. Remove from the heat and set aside.
For the Pistachio Praline, spread the pistachios onto a baking tray lined with baking paper. Place into the oven to roast until golden, about 5-6 minutes then remove from the oven and set aside to cool.
Meanwhile, place the sugar into a small frypan over medium heat and melt until deep golden in colour then remove from the heat. Pour the caramel over the roasted pistachios and set aside to cool. Once cool, break up into shards and crush in a mortar and pestle to a coarse crumb. Set aside until needed.
For the Pistachio Crumb, combine all ingredients in a food processor and process to a rough crumb. Spread the crumb out onto a baking tray lined with baking paper and bake in the oven until golden brown, about 7-8 minutes. Remove from oven and set aside to cool until needed.
For the Greek Yoghurt Mousse, place the egg whites into a stand mixer fitted with a whisk attachment and whisk on high until soft peaks form.
With the mixer still running, gradually pour in the sugar and continue whisking until glossy and stiff peaks form. Ensure that the sugar granules are fully dissolved.
Transfer the meringue into a large bowl and gently fold in the yoghurt through the meringue until well combined.
To serve, use a 6cm cookie cutter to cut out four circles of the Sponge Cake then cut each circle in half horizontally.
Place a deep 6cm ring mould onto the serving plate, fill base with thin 5mm layer of Pistachio Crumb, followed by some Greek Yoghurt Mousse and Vanilla Cherries. Top with a layer of Sponge Cake followed by more Greek Yoghurt Mousse Vanilla Cherries, Pistachio Praline, Sponge Cake and finally a layer of Greek Yoghurt Mousse.
Top with some remaining Vanilla cherries and Pistachio Praline. Drizzle with some of the syrup from Vanilla Cherries then carefully remove the ring mould and serve.