Preheat the oven to 400 degrees F. Grease and line a 9-inch springform pan.
Beat the whites to stiff peaks in a bowl. Beat in the yolks, one by one. Continuing to beat, add the sugar and vanilla, and finally the flour. You should have a very high, moussy batter.
Pour the batter into the pan and bake until golden on top, risen high, and a toothpick inserted in the center comes out clean, about 1 hour. Be sure it is fully cooked when you take it out - it is a big cake. Let the cake cool 15 minutes. Remove the sides of the pan and let cool completely. Transfer the cake to a serving platter.
Cover with blackberries and white currants. Serve with whipped cream, creme fraiche, parfait, or ice cream.
Recipe courtesy of Laura Calder