Preheat the oven to 360°F. To make the meringue, separate the yolks from the egg whites. Whisk the egg whites until they form stiff peaks. Add the sugar and whisk until smooth. Put the mixture aside. For the cake layer, melt the butter and let it cool while you prepare the other ingredients. Whisk the egg yolks and sugars. Mix the flour and baking powder together. Add the flour mixture into the egg yolk mixture, alternating with the melted butter and the cream. Pour the batter into 2 loose-bottomed cake tins (9”) that have been lined with baking parchment. Smooth the surface with a spoon. Gently spoon the meringue on top of the cake mixture. Bake on the bottom rack of the oven for approximately 25 minutes. Cool completely and remove from the cake tins. Whip the cream. Flavor the cream with vanilla sugar, if preferred. Put 1 of the cakes onto a serving plate. Top with berries, whipped cream, and jam or lemon curd. Place the other cake on top of the fist. Garnish the cake with the rest of the berries and some flowers, if preferred. Serve the rest of the whipped cream in a bowl with the cake.