Mix the flour with the baking powder and 150 g sugar. Whisk the buttermilk with the eggs and the vanilla flavor and slowly pour into the sugar-flour mixture. Mix with the mixer to a smooth dough.
Line a baking sheet with parchment paper and spread the batter on it. Now distribute the currants evenly on the dough. Sprinkle with 100 g of sugar.
Put the tray in the cold oven and bake the cake at 200 ° C top / bottom heat for about 30 minutes.